Jeremy David Affeldt (; born June 6, 1979) is an American former professional baseball player. He pitched and batted left-handed and played in Major League Baseball (MLB) for the Kansas City Royals, Colorado Rockies, Cincinnati Reds and San Francisco Giants.

Affeldt was a third-round draft pick by the Kansas City Royals in 1997 MLB draft. He made the team in 2002, and started part of the year for them. In five seasons with the Royals, Affeldt bounced back and forth between the starting rotation and the bullpen. In 2006, he was traded to the Colorado Rockies at the trade deadline, and was a member of the Rockies 2007 World Series team. After one season with the Cincinnati Reds, he signed with the San Francisco Giants in 2009, where he was a member of the 2010, 2012, and 2014 World Series championship teams.

Early life Jeremy David Affeldt was born on June 6, 1979, in Phoenix, Arizona, to David and Charlotte Affeldt. His father was a member of the United States Air Force, and Affeldt lived in Guam, Merced, California, and Spokane, Washington, growing up. While in Merced, Affeldt and his father would frequently attend Oakland Athletics games, and Affeldt enjoyed watching Mark McGwire, Jose Canseco, and Dave Stewart. Affeldt attended Northwest Christian High School, a Division 2-B school in Colbert, Washington. He participated in three sports while there, but it was baseball that drove several major league scouts to the school to see him pitch. He graduated in 1997.

Professional career Draft and minor leagues Affeldt was drafted by the Kansas City Royals in the third round of the 1997 MLB draft. Affeldt ultimately decided not to accept a scholarship offer to play college baseball for his hometown Gonzaga University. He spent 1997 pitching for the rookie–league Gulf Coast League Royals. While with them, he went 2–0 with a 4.50 ERA in ten games (nine starts).

Affeldt improved with the GCL Royals the next year, going 4–3 with a 2.89 ERA in twelve games (nine starts). His performance even earned him a promotion to the single-A Lansing Lugnuts. Affeldt did not do well in his time with them, though, as he went 0–3 with a 9.53 ERA in six games (three starts).

In 1999, Affeldt spent the entire season with the Royals' single-A affiliate, which had changed to the Charleston Alley Cats during the offseason. Although he only went 7–7, he had a 3.83 ERA in twenty–seven games (twenty–four starts).

Affeldt pitched with the Wilmington Blue Rocks of the single-A advanced Carolina League in 2000. While with Wilmington, he led the entire Kansas City Royals' organization (and the Carolina League) with fifteen losses (to go with only five wins). He also threw seventeen wild pitches. However, his ERA was 4.09, and the Blue Rocks were only a half–game ahead of the worst team in the league (the Potomac Cannons).

2001 was a better season for Affeldt, as he went 10–6 with a 3.90 ERA in twenty–five starts for the double-A Wichita Wranglers. He was selected to pitch in the Texas League All-Star Game, and he was named to the postseason All–Star team.

Kansas City Royals (2002–2006) 2002 Affeldt was not expected to make the Kansas City Royals' roster in 2002, but he was added to the bullpen after he had an 0.64 ERA and fourteen strikeouts (to go with just two walks) in fourteen innings in Spring training. His major league debut came on April 6 against the Chicago White Sox. He pitched two innings, giving up three hits and a run in a 14–0 loss. On April 24, Affeldt picked up his first major league win by pitching 3.2 innings of relief in an 8–2 win over the Detroit Tigers.

Affeldt's time in the bullpen did not last long. On May 3, he replaced Bryan Rekar in the Royals' starting rotation. In his first start, he pitched four innings, gave up one run, and earned a no–decision in a 4–3 loss to the Baltimore Orioles. Affeldt's time as a starter garnered so-so results, as he was 0–4 with a 5.45 ERA in seven starts. In his last start, on June 8, Affeldt picked up the loss as the Royals fell 11–3 to the St. Louis Cardinals. After getting pulled in the fourth inning due to an injury, Affeldt was placed on the disabled list with fingernail and blister problems.

After making three rehab starts in Wichita, Affeldt returned to the Royals on August 2 and threw a perfect inning against the Minnesota Twins. He remained in the bullpen for the remainder of the 2002 season. After the season, he pitched in a winter league in the Dominican Republic.

2003 In 2003, Affeldt found himself competing with Runelvys Hernández for the first spot in the Royals' starting rotation during Spring training. Because Tony Peña, the Royals' manager, was unable to decide which one would be the ace, he flipped a coin to determine who would be number one. Hernández won the toss.

Affeldt was placed on the disabled list after only four games with blister problems again. His time on the DL was brief and he returned to the Royals on May 6. On May 28, he struck out a career high eight batters in a win against the Minnesota Twins. Later, on June 6, he notched his first hit.

Affeldt's final start of the year came on July 23, in a game he won against Minnesota. After the start, the Royals moved him to the bullpen to try to fix his blister problems. The move was originally thought to be temporary. While in the bullpen, on August 3, he got his career first save in a 2–0 win over the Tampa Bay Devil Rays. On August 21, the Royals announced that Affeldt would spend the rest of the year in the bullpen. Two days later, he got another save against Minnesota. He picked up two more saves before the end of the year and finished with a 7–6 record and a 3.93 ERA. After the season, to try to help with his blister problems, he had part of a fingernail on the middle finger of his left hand removed. Also, the Royals announced that if he developed blister problems again, he would be sent to the bullpen for good.

2004 In 2004, Affeldt was named the Royals' third starter out of Spring training. He went 0–3 with a 5.24 ERA in eight starts. His final start of came on May 18 against the Texas Rangers. Affeldt gave up five runs in four innings and received a no–decision in a 7–6 victory by the Royals. Afterwards, although his blister problems had not resurfaced, manager Tony Peña named him the Royals closer on May 21 due to poor pitching and injury problems with the other Royals closers.

Affeldt blew his first save opportunity of 2004 against the Oakland Athletics on May 22, but he converted in his next outing on May 25 against the Detroit Tigers. He converted eight of ten save opportunities before he was placed on the disabled list on June 27 with a partially torn rib–cage muscle. He was out for almost eight weeks.

After making four rehab appearances for AAA Omaha, Affeldt returned to the Royals on August 21. He made his first appearance since returning from the DL on August 22, but he did not get another save until September 1 in a 1–0 victory over the Tigers. He picked up four more saves to finish the year with a career–high 13 saves and a 4.95 ERA.

2005 In 2005, Affeldt was again expected to be the Royals' closer. However, he did not get a save opportunity until April 16 against Detroit, and he was unable to finish that game because of a groin injury that landed him on the disabled list again. After rehabbing in Omaha, Affeldt returned to the Royals on June 4. He was no longer the closer, however, because Mike MacDougal had been closing well in his absence. Affeldt was not healthy for long, as he returned to the disabled list on June 20 after reaggravating the groin injury.

Affeldt returned to the Royals on July 7. Through July 27, he had a 2.18 ERA. He did not give up more than one earned run until August 5, when he got his first loss of the year against the Oakland Athletics. However, Affeldt had a 12.71 ERA in his next eighteen appearances, which raised his ERA to 6.93. He held opposing batters scoreless for the final nine games of the season to bring it down to a season–ending 5.26.

2006 Affeldt returned to Kansas City's starting rotation in 2006 when he was named the fourth starter during Spring training. However, he was moved up to the third spot before the season began when Runelvys Hernández was demoted to the fifth spot. Affeldt struggled as a starter, going 2–5 with a 7.80 ERA in nine starts. His final major league start came on May 27 against the New York Yankees. He gave up ten runs on eleven hits in a 15–4 loss. After the start, he was sent to the bullpen, and Bobby Keppel filled his place in the starting rotation. Affeldt improved in the bullpen, posting a 2.91 ERA there through July 31.

Years later, reflecting on his tenure with the Royals, Affeldt said, "I was pretty frustrated. I wanted to quit. I didn't want to go to the ballpark. I was just failing a lot. I was getting hurt. I didn't understand my role. I bounced around and I just didn't enjoy the game." At the trade deadline on July 31, Affeldt was traded along with Denny Bautista to the Colorado Rockies for Ryan Shealy and Scott Dohmann. Affeldt recalled, "When [Royals General Manager Dayton Moore] traded me, he said, 'I feel like I need to give you a fresh start. You can learn to enjoy the game again.' I have a lot of respect for him now because he saw that. It was a move that had to be made for me to be able to continue playing baseball. I'm very thankful for it."

Colorado Rockies (2006–2007)

With the Rockies, Affeldt was used exclusively out of the bullpen. He got his only save of the season on September 19 in a 12–4 win over the San Francisco Giants. Affeldt finished the 2006 season with a 6.20 ERA in fifty–nine games.

Affeldt spent the entire 2007 season in the bullpen, where he was used as a lefty specialist. Affeldt had a 2.51 ERA through his first fifty–six games of the year. He did not give up a home run until Pete Laforest hit one off of him in an 11–9 loss to the San Diego Padres on August 16. He struggled at the end of the year, with a 7.30 ERA in his final nineteen games. He still finished the year 4–3, with a 3.51 ERA in seventy-five games, and the Rockies made the playoffs as the NL Wild Card. He made his postseason debut on October 4 in the Division Series against the Philadelphia Phillies and gave up one run (on a home run by Ryan Howard) in one inning in a 10–5 win by Colorado. The Rockies swept the series to advance to the Championship Series against the Arizona Diamondbacks. In the first game, Affeldt entered with two outs and the bases loaded with the Rockies leading 5–1. He retired Stephen Drew to help the Rockies win 5–1. The Rockies swept the Diamondbacks to meet the Boston Red Sox in the World Series. Affeldt pitched in all four games of the World Series without giving up a run, but the Rockies were swept by the Red Sox. Affeldt became a free agent after the season.

Cincinnati Reds (2008)

Affeldt was signed to a one–year deal by the Cincinnati Reds on January 23, 2008, to compete for a spot in the starting rotation. He said of signing and competing to start, "My heart skipped a beat when they offered that deal. I went with my heart there." However, he was placed in the bullpen, where he stayed for the entire year. He won his first game as a Red when the Reds beat the Arizona Diamondbacks 6–5 on April 2. He made the three hundredth appearance of his career on May 2 in a 2–0 loss to the Atlanta Braves. His only other decision of the year came on September 3 when he was the losing pitcher in a 6–5 loss to the Pittsburgh Pirates.

Affeldt finished the 2008 season with a 3.33 ERA in seventy–four games. He was also one of only five NL relievers to pitch seventy-five innings and average one strikeout per inning, along with Joel Hanrahan, Aaron Heilman, Hong-Chih Kuo, and Carlos Mármol. Following the season, Affeldt again became a free agent.

San Francisco Giants (2009–2015) 2009