Dimitar Berbatov believes that Chelsea pose the only credible threat to Manchester United's chances of winning a fourth consecutive Premier League title and is confident that the championship will end up back at Old Trafford.

The United striker indicated that he feels Arsenal are not capable of finishing top despite resurgent recent form which has left Arsène Wenger's team seven points behind the leaders, Chelsea, with two matches in hand.

The first of those is at Portsmouth tomorrow night, while United, who are two points clear of Arsenal having played a game more, take on Wigan Athletic.

"I think that we are in a great position," Berbatov said. "There are a lot of games before the end of the season and it will be difficult. I think it will be decided between us and Chelsea but in the end I think we'll end up on top.

"We have great players so let's see what happens. There are a lot of games this time of year and it's a been a bit of a difficult time with the injuries but the players are coming back now.

"The boss knows what he's doing and I'm sure at the end of the season we will be on top."

Berbatov's remarks came as Fabio Capello, the England manager, said that United were not as daunting a prospect as in the past.

"Manchester United were a war machine and they have slowed down," he said in an interview with La Gazzetta dello Sport. "Chelsea are fine but the other teams are getting better – Arsenal and Aston Villa and then those teams further behind.

"[Roberto] Mancini's Manchester City and [Alberto] Aquilani's Liverpool will pick up speed."