Birmingham manager Alex McLeish believes Manchester United can emulate Arsenal and go through the season unbeaten in the Premier League.
McLeish believes it is "ominous'' that United have still to taste defeat despite not firing on all cylinders during the early part of the campaign.
He also feels the experience of his mentor at Aberdeen, Sir Alex Ferguson, will again be crucial and give United the upper hand during the run-in.
McLeish, whose side visit Old Trafford on Saturday, said: "I think it's ominous, the fact that they've got to this stage unbeaten and their form is probably gathering momentum.
"They are probably looking better now than in the earlier part of the season when they had a lot of draws. It's amazing that they are unbeaten and I think that they can only get better.''
Asked if they could go throughout the league campaign without losing, McLeish added: "Of course they can. It would be a hell of an achievement.
"In terms of the title, it is such a tight league but Manchester United have so much experience of this situation. There is no man who has got greater experience than Sir Alex when it comes to the run-in, and the run of games after January.''
McLeish has challenged his players to relish the task facing them against United.
"The spirit in the dressing room has never been in doubt," McLeish said. "Players have always gone right to the very end of games. We know Old Trafford is a very difficult place to go and win but it is a great challenge for the players.
"It is a fantastic arena and the pressure is off us, in that we won't be favourites to win the game. But it is not worth getting out of bed in the morning if you don't think you can go and do something. We've got to go there and believe we can surprise them, surprise everyone.
"It is a privilege for the boys to be playing professional football and it should be their ambition to go to places like Old Trafford and show how well they can do.''
Goalkeeper Ben Foster will return to Old Trafford for the first time since his £6 million summer move to Blues after recovering from a finger injury.
Ferguson is looking for a new goalkeeper but McLeish believes his judgement should not be questioned in allowing Foster to leave.
"I'm sure Ben will relish going back. Hopefully he's not kept too busy in the game! Sir Alex just felt he couldn't hold onto Ben any longer and he was bursting to get regular first-team football.
"It has benefited Ben, without question. He's been in super form, very consistent. Sir Alex has been in the game a long time in the game. It's difficult to say he doesn't make the right decisions with any of the decisions he makes. I'm sure United will be okay in terms of replacing Van der Sar (when he eventually retires).''
Birmingham striker Cameron Jerome and winger Sebastian Larsson are available after missing the derby against Aston Villa through hamstring and hip problems respectively.