While United are only three points behind leaders Chelsea, their defence has not been as sturdy as it has been in recent years, with leads being squandered in a number of games. They are the only unbeaten team in the competition, though, something that has not escaped Martinez's attention, and he has warned his players that nothing but their best will be good enough on Saturday. "Manchester United are unbeaten in 18 games in the league and that shows you that there are many reasons to have a slower start than many people expect," he said. "But in my eyes Manchester United are just where they want to be. They are starting to get the important players reaching their moment of form. "They've got injured players that are going to come back just at the right time and they're just sitting in a very good position in the table just to peak at the right time in the campaign. "We know that on Saturday we'll have to be at our best to be able to compete against the most experienced side in the Premier League." Wayne Rooney could make his return to action for United and, while Martinez feels it would be symptomatic of his side's luck if the England striker does play, he accepts United pose a huge threat regardless. "It's been that sort of season so far," he said. "In football you need to be lucky as well as working hard and we haven't been too lucky this campaign, but if it's down to Wayne Rooney or not Wayne Rooney, we all know that we're playing against a fantastic team and it's going to be down to us. "We're going to need to be at our best if we want to compete with whoever we're going to play because you're playing against a very experienced side full of experience, full of talent, full of quality, and we'll have to be ready for whoever we'll be playing against." If the Spaniard feels that luck is not on his side ahead of the game, then form certainly is not. United are one of two clubs Wigan have not beaten in their 78-year history, the other being Nottingham Forest. "The only one left in the Premier League is Manchester United, so it's been something going on in the history of our football club, we don't see it as a real problem," Martinez added. "I think we're looking at it as a real challenge, something the players want to change and something, if you look at the stats, nobody would expect Wigan Athletic to get anything at Old Trafford, so it's a real good challenge. "We know we need to be at our best to compete against one of the best teams in European football and I just feel the squad is ready for it."
