Strachan said Manchester United's display was the best he had faced
Celtic manager Gordon Strachan refused to criticise match officials following his side's 3-0 Champions League defeat to Manchester United.
There was a suspicion of offside at United's first two goals, which were both scored by Dimitar Berbatov.
"The two goals were offside, but I'm not going to scream about them," said Strachan. "I'm a football man and I know when I'm well beaten.
"You need a decision when you come here and to get two like that was a blow."
Strachan was pleased with the effort of his side at Old Trafford but was frustrated by Celtic's use of the ball.
"We cannot be faulted for our guts and determination," he added.
"What we do fall down on is being anywhere as good as them at passing the ball to each other.
"We gave the ball away unnecessarily eight times in the first 15 minutes, which is a problem. I try to mould a team where everybody can pass the ball and tonight that didn't work.
"Physically, we couldn't match them and that told the longer the game went on.
"I'm just pleased that we had enough guts to stay in there and it wasn't a rout because that's happened here a few times."
We'll try our best to give a performance the next time we play. We'll try and make a decent game of it
Celtic manager Gordon Strachan
Holders United are yet to lose a goal in Group E and visit Celtic Park for the return fixture on 5 November.
"Over the last couple of years, we've played some terrific sides, but that's the best," said Strachan.
"It's one of the best performances I've ever come across in watching European football. You will need to be some team to beat them.
"We'll try our best to give a performance the next time we play. We'll try and make it a decent game of it."
Celtic were without several first-team regulars for their trip to Manchester, including strikers Georgios Samaras and Jan Vennegoor of Hesselink, and Strachan is unsure whether he will have his players back in time for United's trip to Glasgow.
"Hopefully we'll have players that can help us out. I don't know if we'll have a big change in personnel," added Strachan.
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