The Tigers recalled left-hander Daniel Norris from his Minor League rehab assignment on Tuesday, but immediately optioned him back to Triple-A Toledo, where he made his last two rehab starts, including six innings of one-run ball Monday night.
Though the Tigers could technically recall Norris a few days later if Greene goes on the DL, he'd have to start on three days' rest. That's not happening, especially for a young pitcher coming off a back injury.
That leaves left-hander Boyd, who pitched the final 4 2/3 innings for Detroit on Sunday, and top prospect Michael Fulmer, who's scheduled to start for Toledo on Thursday morning. Considering the Twins, who host the Tigers on Friday, have struggled against lefties, the matchup strongly favors Boyd.
The decision could well come down to how much time Greene is expected to miss. Since the Tigers optioned Boyd to Toledo Sunday night, the only way he could be back on Friday would be as an injury replacement, meaning Greene would have to go on the 15-day DL. A backdated DL stint would cost Greene two starts before he'd be eligible to return.
If Greene is likely to miss only one start, that could favor Fulmer for his Major League debut, since he could be called up and optioned back without restriction.
McCann begins rehab assignment
Catcher James McCann, who went on the 15-day DL two weeks ago with a sprained right ankle, began a Minor League rehab assignment Tuesday night for Toledo, starting as the designated hitter.
McCann is expected to play at least four games for the Mud Hens before team medical officials evaluate him for a potential return. He's scheduled to catch seven innings for Toledo on Wednesday, DH again Thursday morning, then catch nine innings for the Hens on the road at Charlotte.
Jason Beck has covered the Tigers for MLB.com since 2002. Read Beck's Blog, follow him on Twitter @beckjason and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.