Former Manchester United captain Roy Keane has accused Arsenal of being "weak" and "soft" ahead of his old club's visit to the Emirates Stadium on Sunday.

Keane was distinctly unimpressed with Arsenal's lacklustre performance in their 3-2 defeat against Greek side Olympiakos in the Champions League on Tuesday.

The result leaves the Gunners, who host Premier League United this weekend, in danger of elimination from the Champions League after losing their opening two group matches.

And Keane, who had many battles with ferociously competitive Arsenal stars like Patrick Vieira and Martin Keown during his United playing days, believes Arsene Wenger's side are lacking the right kind of gritty characters these days.

"Listen, they're soft - Arsenal are soft," Keane said in his role as an ITV pundit.

"They're weak. The goals they give away, you've got no chance of winning any big game if you defend like that.

"I think there's certainly a weakness to the group, they look like they lack characters, leaders and winners.

"I enjoy watching Arsenal, I think they're great to watch, particularly going forward. But part of football is, unfortunately, is defending. And mentally, they're weak."