12:10 PM: Anderson has indeed opted out, per Evan Petzold of the Detroit Free Press (via Twitter).
Anderson was a fairly consistent rotation presence for the Diamondbacks and Brewers for the bulk of his career. He has struggled the past two seasons with the Blue Jays and Phillies as he has transitioned into more of a swingman role. The 34-year-old has logged time in the Majors in every season since 2014. He has compiled 190 appearances (176 starts) with a 4.20 ERA/4.66 FIP across 938 2/3 innings over the past eight seasons.
This year, he’s been starting in Toledo for the Triple-A Mud Hens. Across 15 starts and a pair of relief appearances, Anderson has a 4.63 ERA over 70 innings of work. The Tigers have had plenty of rotation issues of their own, but they have yet to call upon Anderson to help fill the void.