Tigers manager Jim Leyland admitted again before the series finale with the Twins that he was unsure when Boesch would return.
"I don't know, I can't figure that one out; I just kind of stay out of it," Leyland said. "He said his forearm's all fine, the biceps felt fine. Something didn't feel fine."
Boesch has played in eight games (seven starts) since the injury, while missing 10 games. Of the games he has played in, Boesch has played nine innings just three times.
Boesch has hit .240 while dealing with the injury, collecting six hits in 25 at-bats, including a double and a walk.
"What worries me about Boesch is he's one of those guys that when he doesn't play for a while, he gets out of sync," Leyland said. "And I don't got time to be experimenting. So I just got to hope for the best. I want him back, he's a big key for us."
Boesch said he expected to swing Monday to test how he was feeling.