Michael Carrick has urged his teammates against complacency when United take on Braga Tuesday, despite the Red Devils picking up maximum points in their first two games to lie at the top of their group.
"We are not getting carried away," Carrick told PA Sport. "We cannot afford to think that just because we have had a good start it is going to be an easy ride. That is not the case.
"It could come back and bite us. We will go into this game like any other and just look to put ourselves in an even better position without looking too far ahead. It can be quite tough in the Champions League to judge (who will qualify from each group).
"Some people might pick out two teams in a group and say they will be the top two and the others will struggle. Quite a lot of the time, that is not the case.
"It isn't necessarily the teams that catch your eye who are the ones that cause you problems. We know even in Cluj, it wasn't straightforward. The lads had to play well to get a result. That is the nature of European football.
"Braga are a good team. You have to respect them for getting to this stage to start with. It is not easy in any league to go through the whole season near the top. You have to respect them. They are going to be of a certain standard and we have to match it."
Carrick believes sealing progress to the knockout rounds early will help United settle down in the Premier League as well. "It does help the league form if you can get through early," he added. "The manager can change things around and rest players.
"He can use the squad and give players game time. The pressure is off. He can start planning ahead knowing the next stage is already secure.
"It's not always possible though. Sometimes it can go down to the last game, which in itself is not always a bad thing. But it's definitely better to get it done and dusted. We hope we can do that."
