Manchester United manager Sir Alex Ferguson is wary of the threat Blackburn will pose at Old Trafford on Saturday despite the woeful away form of the visitors.
Sam Allardyce's men have lost all their matches away from home this season and their last nine in total, conceding six goals at Arsenal and five at Chelsea.
Allardyce spoke earlier this week about the need for his side to overcome their poor away form, but Ferguson believes the former Bolton manager is building something significant at Ewood Park.
"I saw them against Burnley recently and they played really well in that game," Ferguson said on Friday.
"They have always been difficult to beat at Blackburn and I think Sam has built a different team from Mark Hughes's Blackburn.
"Quite a few decent players have left like David Bentley and Stephen Warnock and players like that and Sam has had to pick up the thread of what was left and replacing players of that quality was not easy."
Blackburn have not been helped by the swine-flu virus that has swept through the camp in the last 10 days, forcing David Dunn and Christopher Samba to miss last weekend's 5-0 defeat to Chelsea.
It has led to a testing week for Blackburn but Ferguson believes that Rovers are over the worst of the situation before he revealed that, thankfully, his club is yet to be hit with the infection.
"We have not had it touch wood," Ferguson said. "I think Sam had a big concern last week when I spoke to him before the Chelsea game.
"But Dunn was back during the week and came on as a substitute against Peterborough so he will be fit. I don't know about Samba but I think they have got to grips with it.
"It's an interesting thing. Flu does happen. Whatever you call it, you had Asian flu a couple of years ago with players missing games. Fortunately, so far, we have been okay."
United are not blessed with an overly healthy squad themselves with a myriad of injury concerns to senior players.
First choice central defenders Nemenja Vidic and Rio Ferdindand are both a doubt with calf problems, Ryan Giggs could also be sidelined. while South Korea midfielder Park Ji-Sung is looking at least another three weeks out after picking up a knee injury when on international duty a fortnight ago.
"We have some doubts," Ferguson confirmed. "Ryan Giggs is a doubt but we hope he will be ok, Ferdinand and Vidic are both doubts and we will have to see what they are like."
United lost their last Premier league encounter last weekend as they succumbed to arch-rivals Liverpool which breathed life back into the Merseyside club's season in a tempestuous afternoon at Anfield.
Ferguson did not wish to discuss that encounter and is more than happy that his side have moved on from that loss, pointing to his side's 2-0 win at Barnsley in the League Cup on Tuesday as evidence that the Liverpool game is out of his side's system.
He said: "We had the game on Tuesday, you don't have any time - you have to get on with life. I thought we did alright on Tuesday."
