Carlo Ancelotti's Premier League leaders have lost two of their last three matches, the most recent defeat a 3-0 drubbing at home against Sunderland. They will also be without key players John Terry, Alex and Frank Lampard for this weekend's clash. McLeish acknowledges Chelsea have strong players to come in for their injured stars, but claims his team feel they can pull off a surprise. The former Scotland manager said: "The big teams don't lose too many in succession, but we're in our own back yard, and we have to believe that this is achievable and we can win it. "I'm not saying that we will do it, but we can do it. "We've got to ensure that Chelsea are going back to London on the coach saying, 'St Andrew's is a tough place to go to'. "We did that with a lot of the big teams last season, but we were unlucky against Chelsea when Chucho (Benitez) scored a perfectly legitimate goal which was ruled out. "Chelsea have got some injury problems, but they still have phenomenal players in the squad who can easily turn it on when they want." McLeish hopes his players are able to capitalise on any doubt that might manifest itself in Chelsea's play. "They're only human, and players can be apprehensive from time to time," McLeish said. "When the confidence is high, there's no stopping footballers, but when the chips are down a wee bit you can feel that apprehension. "If there's a opportunity for us then we have to try and grasp it. "We've got to gather points for very different reasons, but it's a great challenge for us." Despite Sunderland winning at Stamford Bridge using an attacking 4-4-2 formation, McLeish has urged caution to those people now espousing the opinion that Chelsea are vulnerable if teams go at them from the first minute. He said: "Sunderland last week exploited the players who were missing, but Chelsea could have been ahead in the first half hour, so I guess you need a little bit of luck as well. "That wouldn't go amiss for us as well. I don't think we've had the rub of the green. "We should be a few points better off, but that's spilt milk now and we have to get on with it."
