Throughout the course of his career, Walker played for multiple teams. He spent the first four seasons of his major league career with the Seattle Mariners. After 2016, the Mariners traded him to the Arizona Diamondbacks for Mitch Haniger, Jean Segura, and Zac Curtis.
After 2017, Walker spent little time pitching for the Diamondbacks, as he spent time recovering from a UCL tear in his elbow.
In 2020, Walker found his way back to Seattle on a one-year/$2M contract. Walker recorded a record of 2-2 in five games with a 5.00 ERA before the Mariners traded to the Toronto Blue Jays the same year.
With the Blue Jays in 2020, Taijuan Walker pitched some of his best baseball. He went 2-1 in six games with a 1.37 ERA. His impressive 2020 season upped the market for him this offseason.
The bullpen should get better this season with the offseason upgrades the Mets made on the backend. Those signings include Trevor May, Miguel Castro, and Sean Reid-Foley. The mainstays being Dellin Betances, Edwin Diaz, and others.