Squad rotation.
It's based on the premise that they're all happy being squad members. Caicedo was running on fumes at times last season, being able to replace him with Bissouma would mean we'd have got even more out of Caicedo when he played. And playing Bissouma there would mean the drop off...
I'm convinced that if we had (a fit, happy etc)White, Trossard and Bissouma in the squad this past season we would have finished top four. Might have got to the cup final too.