It's a long season and a ridiculous run of fixtures - you saw with Travis and Tronstad in January last year, you simply can't run the same players out there for 90 minutes every week.
Ohashi will break down pretty soon if he's not given a rest. Gudjohnsen has been targeted twice for a rest in the last two games (of the pair of them). We need another CF in January to rotate in if we're sticking with this system.