Defender Jonny Evans has admitted Manchester United must eliminate sloppiness from their play.
United take on Real Sociedad in the Champions League at Old Trafford aiming to gain some confidence in Europe after some disappointments on the domestic front that has seen David Moyes' men take only 11 points from eight matches.
Moyes himself said United were guilty of conceding possession too easily in their last game, the 1-1 draw with Southampton, and Northern Ireland international Evans agreed.
Evans said: "We are disappointed, we watched part of the [Southampton] game back and it was clear our performance was not up to scratch, especially in possession, giving the ball away and being quite sloppy.
"Being Manchester United we want to control games a bit better than we did against Southampton.
"As players we know we have not played well enough as individuals and as a team and looking at ourselves we want to make sure we raise our level and produce better performances."
Four key players were absent from United's training session ahead of the Real Sociedad match - Danny Welbeck, Tom Cleverley and central defenders Nemanja Vidic and Rio Ferdinand, though Moyes said Welbeck and Cleverley have a chance of being fit for the game.
Of more concern to Moyes is his team's performances, and he added: "We want to improve results, that's obvious. We want to improve on our performance too, we gave the ball away too much in our last game and we have to do better when we are in possession.
"We have had periods of good play but maybe not continuously, which is something we have been working on in training."
Moyes confirmed that Belgium-born midfielder Adnan Januzaj has been added to the Champions League squad as a home-grown player and could make his debut in the competition.
The 18-year-old signed a new five-year contract last week and Moyes said: "He is now available [for the Champions League] by the way his date of birth works.
"He's an exciting young player making good progress all the time and he is someone who is going to play a big part in the future of Manchester United, he's an exceptional talent."