I'm not sure why anyone would use Reyes' recent struggles toward the tail end of an All-Star season as a pretty successful closer to forecast his future, especially as a starter.
It's a different job. Completely.
He's a career starter who was thrust into a highly volatile and unfamiliar role for the betterment of the team, and he took it and ran with it the best he could.
Like a lot of closers, he hit a wall.
Starters who transition to the bullpen usually wind up prioritizing two or even one of their pitches. Usually that's because there other pitches are not good enough and that's how the wound up in the bullpen in the first place. That's not he case for Reyes. He's mostly tabled his curve and changeup and that's a bummer, and part of the reason I think he should be stretched back out as a starter moving forward next season.
A lot of assumptions are being made that the max-effort, closer version of Reyes is what he would be as a starter.
If that's the case, no it would not work.
But I don't assume that will be the case.
Different roles require different approaches.
Lots of folks jumping at the chance to kick Reyes when he's down. I don't get it. He's been team-first guy this season and has ran into a wall even the best closers hit from time to time. This team would have been cooked a long time before now without him. I'm not saying that justifies more save opportunities. It doesn't at this point. When a closer falters, you've gotta make a change. I am going to have to be convinced Reyes is not a difference-making starter for this team. A predictable stumble as closer isn't convincing.
Paul DeJong's disappointing season has been covered exhaustively by the PD.