Pundit Alex Rae insists Ange Postecoglou can't expect to play "basketball" every week and get results with Celtic.
Since arriving at Celtic Park, the Australian has stuck to his football philosophy and pushed for an all-out attack and high press no matter the opposition.
That includes in the Europa League, with Bayer Leverkusen's turnaround victory throwing Postecoglou's tactics into the limelight.
Rae reckons that Postecoglou should have taken a different approach with Parkhead taking the lead twice in Germany.
The former Rangers midfielder believes questioned the changes made by the Celtic boss and insists he needs plenty of new recruits in January.
Rae told Clyde 1 SuperScoreboard: "I think that January is really big for Celtic, because the bench is actually quite weak.
"You have one or two players that can actually strengthen them (off the bench).
"When the players came off the other night, I thought it was fairly evident that there was a weakness there. When you are making changes, you are actually weakening the team.
"He (Ange Postecoglou) has to learn that he has to dig out a result having got in a brilliant position.
"It's about managing the game through at that particular time.
"You can't play basketball football against them. You attack, we attack - they have got too much quality at that level.
"When Jota was still on I thought they were a real threat on the transition, but I think it goes back to big Ange asking those players to play 90 minutes time after time.
"At the moment he doesn't have strength in depth, and January is a massive window to get that quality through the door."
