2004 saw Zumaya begin the year pitching for the High-A affiliate Lakeland Tigers, before a late season promotion to the Double-A Erie SeaWolves.

Zumaya began the 2005 season back in Erie; however, his results were much improved from 2004, and he was soon promoted to the Triple-A Toledo Mud Hens.

While refusing to disclose the actual source of the injury, and calling the Guitar Hero story his "final answer", he also admitted that it was "some bogus stuff.

"[6] Zumaya's future was then clouded by injury: in May 2007, he ruptured a tendon in his hand, requiring surgery and 12 weeks rehab.

The next day, he made his first major league appearance following the injury, pitching to one batter in a game against the Cleveland Indians.

[8] He was reactivated by the end of April; however, he was placed back on the 15-day DL following a July 18 appearance against the New York Yankees, where it was reported he could barely move his right (throwing) arm.

On June 28, 2010, Zumaya injured his elbow in the eighth inning, while pitching against the Minnesota Twins' Delmon Young at Target Field.

[12][13] On February 25, 2012, Zumaya tore an ulnar collateral ligament in his throwing elbow 13 pitches into a live batting practice session, requiring Tommy John surgery and ending his 2012 season, in which he was guaranteed to earn $400,000.

On July 3, 2006, at McAfee Coliseum in Oakland, California, Justin Verlander, Zumaya, and Fernando Rodney each threw multiple fastballs measured in at over 100 miles per hour (160 km/h), becoming the first time in MLB history that three pitchers on the same team had done so during a game.

On July 4, 2006, at McAfee Coliseum in Oakland, California, Zumaya threw a pitch measured at 103 miles per hour (166 km/h), thus tying the "unofficial" record held by Mark Wohlers.

[16] Similarly, on May 20, 2006, Zumaya gave up a grand slam to Ken Griffey Jr. on a pitch that FSN Detroit's radar gun measured at 104 miles per hour (167 km/h).

[17] Zumaya hit 104 miles per hour (167 km/h) on the Comerica Park radar gun on August 7 while pitching against Minnesota Twins infielder Nick Punto.

[19] In an interview for Detroit radio station WRIF, former Tigers pitcher Denny McLain stated that he believed the numbers on stadium and television radar guns were inflated.

After the 2006 season, The Bill James Handbook published a list of pitchers and the number of their pitches thrown at 100 miles per hour (160 km/h) or more.