Absolutely. And there can be little niggles/injuries which do need rest, but could stand up to 10 or 20 minutes play, if needed, but a full 90 minutes could cause real problems, or a major setback.
There's a vast difference between being able to carry a knock for a whole game (which presumably he wasn't) and being able to carry that knock for part of a game, if needed (which obviously he will have been, otherwise CH wouldn't have had him on the bench).