The Mariners have moved Chris Flexen to the Bullpen

The Seattle Mariners, in an interesting move, have shifted the role of Chris Flexen from the rotation to the bullpen. This was done on a day when Diego Castillo and Dylan Moore were reactivated from the IL but also comes off the heels of the Mariners acquiring Luis Castillo, which pushed the rotation up to 6.

Seattle has used a 6-man rotation in the past and has done so effectively. It was done to limit innings after the shortened 2020 season, but it did work. However, I want to talk about how this move makes sense even while it might be a little puzzling.

Chris Flexen is now in the bullpen for the Mariners

The rotation before this move consisted of Luis Castillo, Robbie Ray, Logan Gilbert, Marco Gonzales, Chris Flexen, and George Kirby. Something to be aware of though, is that George Kirby is eating through innings like crazy. He’s had a promising and impressive rookie year, but his arm health is definitely a priority.

I think that Flexen provides a lot of breathing room. You get Kirby to get even closer to his innings limit here in the next few weeks, he can then transition to the bullpen himself or spend some time back in the Minors. Either way, when this happens we would have Flexen ready to come back into the rotation and contribute.

It could potentially make sense to just transition George Kirby to the bullpen now at this point, as then he could spend the rest of the year slowly churning through his innings and still contributing.
I think the answer comes down to the productivity out of the rotation as well as the ability to have a true long-relief out of the bullpen.

Having a long reliever is a tremendous asset in a playoff push, because starters getting roughed up is inevitable, and you need some way to recover. Remember too, that Matt Boyd will be back at some point to potentially provide even more relief help.

I think this was the right move, and Flexen will do well as a long reliever through the playoff push this year.