Ronaldo was unable to turn things around as a second-half substitute
Sir Alex Ferguson says his Manchester United team will soon return to form following their goalless draw with Villarreal in the Champions League.
Having collected just one win and four goals in six games, United face Premier League leaders Chelsea on Sunday.
"We are a bit short but the games will bring us on," said Ferguson.
"We will improve from now. We have a little bit to go yet. But once the sharpness of play comes, I am sure the goals will come as well."
It has been a lacklustre start to the season for the 2008 Champions League winners and Premier League champions.
They needed penalties to overcome Portsmouth in the Community Shield after a goalless draw, and drew 1-1 with Newcastle in their opening league game.
They won 1-0 away at Portsmouth but then lost 2-1 to Russian side Zenit St Petersburg in the Uefa Super Cup, followed by Saturday's 2-1 loss at Liverpool.
Former Manchester United defender Gary Pallister believes the first few results should be a source of concern for the Old Trafford hierarchy.
"They are simply not playing well enough," he told BBC Radio 5 Live.
"It was unusual for them to be outfought at Liverpool. It's the biggest game on the calendar for Manchester United and they usually put up a good fist of things down there.
"They were outfought on Saturday, they didn't manage to score again last night and the manager's said it's not been good enough."
Pallister is confident United will bounce back to form but said a poor start could prove very costly in the long run.
"What's happened with United over the last two seasons when they've won the Premier League - and obviously last year the Champions League - is they've started really well," he said.
"They've been fit and raring to go right from the start of the season."
He added: "It's unusual to see them have such a sluggish start. OK, (Cristiano) Ronaldo's not been there - and that's a huge miss for any team - but they've got to cope with that.
"They've got the likes of (Carlos) Tevez, (Wayne) Rooney, (Dimitar) Berbatov, they should be performing better right now."
Berbatov missed Tuesday's game against Villarreal because of injury as United failed to create many chances to at Old Trafford.
Their best effort came from Jonny Evans, whose late header hit a post.
However, Ferguson was satisfied with his team's performance and delighted with the return of Ronaldo, who was making his first appearance of the season as a second-half substitute.
Ronaldo has spent two months recovering from surgery but came on for the last 25 minutes against Villarreal.
Ferguson revealed the Portuguese winger was unlikely to start against Chelsea at Stamford Bridge but was delighted to have him back nonetheless.
"That was his first game back so it is a big ask to think about Sunday," said the 67-year-old Scot. "To come back like that, without a practice match or anything, the boy has done very well."
Berbatov, a �30.75m signing from Spurs on transfer deadline day, remains a doubt for the weekend with a knee injury.
"Dimitar has a chance for Sunday but it is too early to say for certain," said Ferguson.
E-mail this to a friend 
Printable version 
Bookmark with:
What are these?