Imanaga has been throwing 150 IP per season and over 6 IP per game since COVID (baseball reference shows only G, not GS). I would think he’s going to find a SP role in MLB. I think another LHSP would be good for the Tigers.
Now, if they were to acquire him and he’d be bumped to the bullpen due to the rest of the rotation being stout, well, I wouldn’t necessarily be adverse to it. But the price tag likely exceeds the role at that point. The bullpen could use another LHP, maybe more so than the rotation. I think they can adequately fill that role at well below what Imanaga is going to receive.