Sir Alex Ferguson is certain Arsenal will slip up in their bid to depose Manchester United as Premier League champions. The Gunners are unbeaten in their 14 league games so far this season and lead United by three points with a game in hand. But, in what is bound to be perceived in some quarters as psychological warfare timed to coincide with the crucial Christmas period, the Old Trafford boss insists they will drop points. He told Manchester United Radio: 'Arsenal are playing well, but it's a long season and they know that, too. They will drop points, there's no doubt about that.' United could have been level at the top of the table with Arsenal had they not failed to beat Bolton 10 days ago and Ferguson admitted: 'We'd like to be three points better off. 'If we hadn't lost to Bolton then we would have been in a great position.' Ferguson also revealed he is pondering how strong a side to field in United's final Champions League Group F game against Roma. The match is for nothing more than pride, with Ferguson's men having already secured top spot in the group and the Italians also having qualified for the knockout phase in second place. With the congested Christmas fixture schedule on the horizon, including a vital Premier League trip to Liverpool, Ferguson said: 'I have a dilemma for the Roma trip. 'Obviously we're already through, and I'd really like some of the young players to get some miles on the clock, but we have to make sure we don't get embarrassed.'