Ole Gunnar Solskjaer says Manchester United made it hard on themselves against Astana on Thursday.
United kicked off their Europa League campaign with a 1-0 victory over the Kazakh side.
The winner came through 17-year-old Mason Greenwood, who finished superbly after 73 minutes in what was his first start for United.
The goal saved Solskjaer's blushes as they laboured throughout the 90 minutes.
Speaking after the game, he said: "We made it hard for ourselves. Games like these, you want to make sure you win the game in the first 20 minutes and you can enjoy it.
"You could see some of our lads needed games but it's pleasing we got the three points."
