The Red Devils have endured a difficult start to life under the Scot, who replaced Sir Alex Ferguson at the start of the season, and suffered an embarrassing 2-1 home defeat to West Brom on Saturday.
And with a tough trip to Ukraine on Wednesday to face Shakhtar Donetsk, Moyes admits they are way off the pace.
“To win the Champions League you have to have five or six world-class players,” he says.
“If you look at Bayern Munich, they have five or six really world-class players and, to win it, you might have to have that in your squad. Look at Barcelona, who had it in the past, and Real Madrid have maybe got it now.
“That's the level you have to get at to win it. We've not got that yet. What we have got is experience and several players who are in that category or close to it.”