Chelsea manager Luiz Felipe Scolari could have been forgiven for having a little smile on his face as Cristiano Ronaldo, Wayne Rooney and Carlos Tevez trudged disconsolately off the pitch at Pride Park last night.

For last May, this Manchester United triumvirate ran riot at times in the Champions League Final, just as they had done all season, as the Blues struggled to contain them.

Fast forward eight months and a Derby side sitting 18th in the Championship having shipped 37 goals in 26 matches contained the trio with relative ease to give Chelsea cause for optimism ahead of Sunday's showdown at Old Trafford.

United have found the net only 29 times in 18 League games this season and never looked like overhauling Kris Commons fabulous first-half strike.

Equally, they were uncharacteristically shaky at the back and even the often myopic Sir Alex Ferguson could not defend his side's display.

"We were so bad that Derby will rue the fact they didn't score more," said the United boss.

"We were lucky. They played to their strengths. Their aerial play was very good and it caused us a lot of bother. The big lad up front, Rob Hulse, caused us problems.

"The only positive to take from the game is the fact we only lost 1-0. It was a fantastic result for us tonight considering the performance."

Okay, so Rooney and Ronaldo only had half an hour to work their magic but still their ineffectiveness was indicative of a wider malaise. What has happened to the trio who scored 79 goals between them last season?

Ronaldo, with mitigation from ankle surgery that delayed the start of his campaign, has consistently failed to produce his best with many observers claiming his frustration is rooted in missing out on a move to Real Madrid.

Rooney is yet to discover how to be consistently effective in front of goal, lurching from goal gluts to barren spells. Having fallen behind Dimitar Berbatov in the pecking order, Tevez appeared to curry favour last night by doing his best to imitate the lazy side of the Bulgarian's game by coasting through much of the match.

Berbatov is yet to fully understand his new team-mates' movement in the final third and that confusion is a key element of United's disjointed displays.

It would be churlish to cynically attack an under-strength United after one defeat though a failure to find the fluidity that made them world, European and Premier League champions last year.

But this combined with Chelsea's excellent away record will give Scolari's side renewed hope. In front of new boss Nigel Clough, Derby made a bright start and took the lead when Commons fired home after 30 minutes.

But it could have been much worse for Ferguson's mixture of experienced internationals - Paul Scholes and John O'Shea - and youngsters - Danny Welbeck and Darron Gibson.

Steve Davies was denied by Tomasz Kuszczak when he let fly from a tight angle and, after the ball fell kindly for the former Tranmere midfielder, Nemanja Vidic did well to block his goal-bound follow-up.

Mile Sterjovski was the next Derby player to have a shot cleared off the line, when Jonny Evans hacked away his first-time effort. Andy Todd was then unlucky to see his lob land on the roof of the net soon afterwards when a poor Kuszczak punch fell at his feet.

And Hulse will still be having nightmares after he missed a chance to make it 2-0 when he fired over late on.

The closest United came to an equaliser was a second-half Ronaldo free-kick that flew inches wide.

The champions will still be favourites to overturn their single-goal deficit in the second leg at Old Trafford on 20 January. But Ferguson will want a significant improvement on this performance against Chelsea on Sunday.