In 1997, Walker signed with the Boston Red Sox but never played for them at the major league level.

In December 2000, Walker once again signed with the New York Mets and played 3 games for them before returning to the minors.

He also played for the Yokohama BayStars of Nippon Professional Baseball in 2004, between his two stints with the Blue Jays.

[8] On November 24, 2012, Walker was appointed as the pitching coach for the Blue Jays, replacing Bruce Walton.

[9] On March 26, 2022, Walker was arrested in Pinellas County, Florida, and charged with driving under the influence.