When rosters expand in September, a 6-man rotation becomes easier with the extra bullpen arm.
Until then, Bieber, Gausman, and Scherzer are the clear top three, and Bassitt isn’t a bullpen fit. That leaves Berríos and Lauer.
Lauer has bullpen experience seems to be a better fit as a longman than Berríos, and he Bassitt now have shorter leashes with Lauer in the pen.
It also gives Lauer useful pen reps ahead of the playoffs, where he could be valuable if a starter falters early.