Rooney, who was excellent again in a deeper role, acknowledges that it is a dangerous habit that needs fixing in order to compete for silverware.
"Obviously it's not nice," he told MUTV. "It's something we need to make sure we stop doing. We can't keep affording to let teams get a headstart on us, especially in the Champions League when it's very difficult to win the game anyway.
"We have to make sure we're more solid than we have been and hopefully we can be in future games."