Sir Alex Ferguson expects Manchester United to face motivated City side in derby Manager Sir Alex Ferguson has no doubt rivals Manchester City will be trying their utmost to upset Manchester United's title ambitions when the two teams meet on Monday. United head into the Old Trafford clash 15 points clear at the top of the Barclays Premier League with just eight games remaining. Even if Roberto Mancini's men prevail, it may only be a stay of execution before defending champions City have to hand the trophy back to their fierce local rivals. And although Ferguson has no intention of offering even that crumb of comfort, he understands where the Blues are coming from. "It'll be a big game for City - they'll want to come and derail us for a spell," said the United boss. The problem for United is one of perception. With their Champions League and FA Cup campaigns now at an end, they have only the league to play for, and that seems to have been secured for some considerable time. The campaign is therefore in danger of turning into a damp squib, a rather extraordinary situation for a team who could yet set Premier League records for number of points and biggest winning margin. Not even the likely return of Wayne Rooney from a groin injury makes that much difference. There is the growing debate over Robin van Persie's lack of goals though, given the previously prolific Dutchman has now gone nine games since he last found the net, the longest barren spell he has endured since joining Arsenal from Feyenoord in 2004. Even thoughts of a goal at Sunderland last weekend have now been dismissed, the winner at the Stadium of Light being officially credited as a Titus Bramble own goal. As a former striker himself, Ferguson is uniquely placed to offer advice in times of such strife. And while he retains a firm belief Van Persie will turn his present situation around, he always remembers the wise words his dad came out with. "My dad always used to say 'make sure you batter the ball, don't tap it or try and side-foot it into the net'," said Ferguson. If the goalkeeper saves it, you can say what a great save.