The extent to which Wayne Rooney has been carrying Manchester United this season has been the subject of debate, but there was no questioning how badly David Moyes's side missed the injured Liverpudlian here.

On the other hand, as Moyes pointed out afterwards, his players have rediscovered that most useful of attributes, finding a way to win. Having seen his starting XI outplayed to an embarrassing extent in the first half, Moyes brought on Danny Welbeck and saw the England forward score an opportunistic goal to give United a sixth successive victory.

"Manchester United won the league last season not always being at their best, and today they found a way to win," said Moyes. "To win two away games in three days takes some doing, especially with a lot of our key players out, so I'm delighted with how they're keeping going, but I don't think it's anything to shout about."

Rooney, he said, is expected to be fit for Wednesday's match against Tottenham. Welbeck can also expect to start after producing a performance, as well as a goal, that changed the course of this game.

"I've said before he's a really, really good player who needs to become a really, really good finisher, and I thought he did great today," said Moyes.

With Rooney left at home to protect a minor groin problem and Adnan Januzaj joining Welbeck on the bench, United lacked almost any attacking threat throughout a first half dominated by Norwich. While Nemanja Vidic's return to partner Jonny Evans strengthened central defence, a midfield composed of Ryan Giggs, Michael Carrick, Tom Cleverley, Ashley Young and Shinji Kagawa left Javier Hernández isolated up front as they tried and for the most part failed to deal with a Norwich axis of Wes Hoolahan, Robert Snodgrass and Nathan Redmond.

It was Norwich who created the first real chance. A patient passing move ended with Snodgrass slipping the ball into the path of Russell Martin running behind Patrice Evra. From a narrow angle the full-back shot firmly and accurately, but United goalkeeper David de Gea dived to his right to make a fine save.

Encouraged, Norwich began to press forward with more belief. Gary Hooper, turning in the penalty area, shot straight at De Gea, and Snodgrass, cutting in from the right, curled a shot wide. The Scotland midfielder was becoming increasingly influential and Giggs was booked for bringing him down as he threatened the United penalty area.

It was the 37th minute before United finally had a direct attempt on goal, Carrick shooting high from well outside the Norwich penalty area. City should have taken the lead soon afterwards, Hoolahan creating space in the penalty area only to drive disappointingly against the legs of Evans.

Moyes switched his midfielders around, Young moving to the left and Kagawa into the centre, but their attacking threat remained negligible. The sight of Martin skinning Evra gave the manager even more to think about during a break in which he replaced Giggs with Welbeck and switched to a conventional 4-4-2.

The improvement was immediate. Young drove just over, though Ruddy had his shot covered, which was more than could be said for De Gea when Redmond, played in by Hoolahan, flashed a shot inches past his far post soon afterwards.

While United's movement and passing were unrecognisable from the first period, however, it took a moment of fortune for them to break through. Ryan Bennett should have cleared, but Welbeck closed him down quickly, and the rebound fell kindly for the England forward to run on, push the ball past Ruddy, and turn it over the line.

"We certainly didn't deserve to lose. We were excellent in the first half, but when you have your best period you have to capitalise and with the quality they have and the changes they can make it can allow them to get back into the game," sighed Norwich's manager, Chris Hughton.