Chelsea manager Jose Mourinho has fired a warning to Premier League rivals Manchester United ahead of their showdown with Arsenal on Sunday, insisting that defeat to the Gunners would leave them with significant ground to cover in the title race.

United trail league leaders Arsenal by eight points ahead of tomorrow afternoon's clash at Old Trafford, with a win for the Gunners enough to open up an 11-point gap over the defending champions.

Mourinho has stopped short of declaring that United would be out of the title picture if they fall to Arsene Wenger's side, but believes that they would be "on the edge" of contention if that scenario unfolds this weekend.

He told The Guardian: "It's on the edge [with a loss] but United is United.

"So even 10, 11 points, I wouldn't say it's over for them. If they lose, in this Premier League, I don't think it's impossible for them to be champions."

The Blues, who are five points back in the current standings, can close the gap on Arsenal to two points with victory at home to West Bromwich Albion this afternoon.