Mize and the Tigers avoided arbitration after agreeing to a one-year, $2.34 million contract Thursday, Mark Feinsand of MLB.com reports.
The Tigers declined Mize's $3.1 million club option for 2025 on Monday.
Mize isn't included on the Tigers' ALDS roster.
Mize allowed one run on three hits across two innings of relief in Thursday's 4-3 win over the Rays. He struck out four.
Tigers manager A.J. Hinch said that Mize will be available in relief Sunday in Baltimore but will likely receive another traditional start during the upcoming week, possibly against the White Sox, Chris McCosky of The Detroit News reports.
Mize came away with a no-decision in Tuesday's 3-1 extra-inning win over the Royals, allowing one run on six hits and four walks over 4.1 innings. He struck out three.
Mize came away with a no-decision in Wednesday's 7-4 win over the Rockies, giving up four runs on six hits over 4.2 innings. He struck out seven without walking a batter.
Mize did not factor into the decision in a win over the Padres on Thursday, allowing three runs on six hits and one walk over 5.1 innings while striking out two.
The Tigers activated Mize (hamstring) from the 60-day injured list Friday, Evan Petzold of the Detroit Free Press reports.
Mize (hamstring) threw a bullpen session Tuesday that was deemed successful by manager A.J. Hinch, Evan Woodbery of MLive.com reports.