SOCCER:ALEX FERGUSON will take a calculated risk in the second leg of Manchester United's Champions League semi-final against Schalke tonight by leaving out several key players to prepare for the potential title-decider against Chelsea on Sunday.

Ferguson, aiming for his third final in four years, spoke at length about the importance of his team not allowing complacency to jeopardise their 2-0 first-leg lead, but the United manager also made it clear he is prioritising the weekend fixture against a Chelsea side that have moved within three points of the league leaders.

Uppermost in his thoughts is to avoid a repeat of what happened last season when United followed up their Champions League exit against Bayern Munich by losing three days later against Chelsea in the game that effectively meant the championship returning to Stamford Bridge.

“If you look at the experience of last year, we lost a Wednesday game against Bayern, and the team was very tired against Chelsea in the next game,” Ferguson said. “That has to have a bearing on my team selection (against Schalke). There will be changes, but hopefully the nucleus of the team will still be good enough to win the game.”

Ferguson can also draw on the memories of playing Wayne Rooney in the return leg against Bayern when he was carrying an ankle injury, subsequently losing his most important striker for key matches of the run-in.

Rooney, once again, has fitness concerns, unable to train because of a tight hamstring, and Ferguson said the team would start with Dimitar Berbatov and Michael Owen in attack. That means Rooney and Javier Hernandez being kept back for Sunday, and Ferguson will also consider resting, among others, Rio Ferdinand and Edwin van der Sar.

“We are still confident on the league front, with a three-point lead and three games to play,” he said. “Two of those games are at home and I’m sure we will hit our targets. We must be favourites because we’re three points ahead but that can evaporate quickly, as we saw on Sunday (the 1-0 defeat at Arsenal). We’re in a great position and, though we didn’t play as well as we know we can at the Emirates, we still have players in good form all over the field.”

Chelsea, he said, could expect a significant improvement from his team on United’s own ground, where they have not lost all season. “It’s always been the case at this club that if we lose a game we recover.”

Berbatov has become an increasingly peripheral figure at Old Trafford, starting only two of the last 12 matches, while Owen has been restricted to only four starts all season. Ferguson, nonetheless, was careful not to say anything about Schalke that could be seen as overly presumptuous.

“Schalke have nothing to lose. That’s the message he (Ralf Rangnick) will be imparting to his team. I think we’ll find they will have a real go because there’s nothing else they can do. The interesting thing about Sunday was that the last four European teams (United, Schalke, Barcelona and Real Madrid) all lost. There are statistics that show the European games do take it out of you. Sunday’s match is a huge one, which is why I have to pick the right team.”

Nonetheless United have never lost a Champions League match at home by more than one goal.