Not to defend Rashford but this is a common phenomenon when coming on in a high intensity game without proper warmup. A couple of sprints and you're completely gassed. It goes back to normal after taking it easy for a couple of minutes. For Rashford it was either counter-attack or tracking back, so there was no chance to recover. Has nothing to do with stamina really.
That said, one would think a professional footballer should avoid this, so it's no excuse.
That said, one would think a professional footballer should avoid this, so it's no excuse.

