MANCHESTER, England (Reuters) - Free from the weight of expectation that Manchester United's number seven shirt brings, Antonio Valencia produced a cracking goal this week which has prompted his manager David Moyes to call for several more.

The Ecuador winger took over the shirt number worn by the likes of United greats George Best, Bryan Robson, Eric Cantona, Cristiano Ronaldo and David Beckham after he was named the club's player of the year in 2011-12.

However, after netting just once last season and putting in some indifferent performances, he asked to have his old number 25 shirt back and in Tuesday's 4-2 Champions League win over Bayer Leverkusen he looked more like his old self.

"He has done very well," Moyes told a news conference on Friday ahead of this weekend's derby at Manchester City.

"They keep telling me that he needed to change his number so we got that changed for him. Sometimes, psychologically, it can make a difference to a player.

"Overall, I've been really pleased with him. I actually said to him today: 'You should be getting yourself seven or eight goals a season regularly'.

"He looked at me and squinted a bit. Hopefully, he knows what I mean ... He's got off to a good start and hopefully he'll get close to the target I'd like him to get this season."

Valencia smashed in United's fourth against Leverkusen with one touch after being set up by Wayne Rooney, who himself is enjoying a new lease of life and has reached the milestone of 200 United goals in all competitions.

The England striker scored twice on Tuesday and netted against Crystal Palace last weekend, drawing praise from his former manager Alex Ferguson whose last words about him had been to say he wanted to leave the club.

STEP UP

While his recent goals, increased sharpness and the fact the club kept hold of him in the face of Chelsea's advances in the transfer window are welcome news for United fans, Rooney has still not actually said he is happy at Old Trafford.

He has two years left on his contract and the club are unlikely to want to wait until he is in the final year of it to start negotiating a new one but Moyes said it was too early to talk about it now.

"I think we just go step-by-step," he said.

"If he could score another two goals at the weekend that would be the next step forward wouldn't it and just keep his form going. I think he's played really well and we want him to maintain it. If anything, I'm asking him to step up again.

"I want him to keep getting better."

Rooney will be hoping to make it goals in three successive games when the Premier League champions travel to the Etihad stadium to face last season's runners-up.

It will be Moyes's first Manchester derby, as it will for his opposite number Manuel Pellegrini, but the Scot said his time as Everton manager and as a player for Celtic meant he was no stranger to passionate cross-city encounters.

"I've experienced derby games in Glasgow and on Merseyside. But as I said every derby in every big city is important to whichever team you support and I understand how important it is for the Manchester United fans," he said.

"We've played well in the last few games and have got a bit of confidence and hopefully we'll try and show that in the game on Sunday."

Having played Chelsea, Liverpool and now Manchester City in the first five league fixtures of the season, Moyes thinks his side have had the hardest start of all the top clubs.

They have taken seven points from four games, the same as City, and with this fixture having proved decisive two seasons ago when United lost it just weeks before City won the title on goal difference, they will be particularly keen to take the points.

(Reporting by Sonia Oxley; Editing by Ed Osmond)