The former Hammers winger believes that Sir Alex Ferguson's Championship team will certainly not relish the thought of facing a Hammers side searching for their first league 'double' of the season.
"Manchester United know it won't be an easy game and I really feel that West Ham have a great chance of getting a result," says Wardie.
"For as long as I can remember, West Ham team's have always been able to raise their performances when the likes of United come to Upton Park and everyone will be fired up for it on Saturday.
"The home form has been magnificent this season and, on their day, they are capable of beating any other team in the Premiership."
While he still keeps a keen eye on the fortunes of his former club, Mark understandably finds it hard to watch the Hammers regularly and cringes when he lists the two matches he has been present at this season.
"I was at probably the two worst games of the season, when the team lost 5-0 at Everton and then 7-1 at Blackburn and, to be honest, they looked like relegation favourites at that point.
"To be fair, though, Glenn Roeder has done a fantastic job to turn it around and the team now look in good shape.
"It has been hard for Glenn, but his approach to the whole thing has been first class and he deserves to succeed.
"The away form has obviously been poor, but that has long been a problem for West Ham, and you can't complain about their record at home.
"The confidence will be high tomorrow because the fans know how well the team can play when a top side comes to Upton Park, and Manchester United will definitely have their work cut out."
West Ham's league record against United at Upton Park hasn't exactly been prolific, with just two victories in the past 19 years, the first of which came in the record-breaking 1985-86 season - Mark's first as a Hammers player.
As the Hammers chased the Football League Championship for the first and only time so far in their history, a 2-1 victory over fellow title challengers United in February set John Lyall's team up for a memorable but ultimately heart-breaking end to the campaign.
Mark remembers the game well - he scored the equalising goal to rule out Bryan Robson's first half opener and was also booked for a memorable foul on Kevin Moran, in the days when yellow cards were a rare occurence.
"It was a fantastic game," he recalls, "and the atmosphere was tremendous. I had one of my best games that season and it was a great comeback after going a goal down.
"I remember fouling Kevin Moran on the touchline by the Chicken Run and he went crashing into the advertising boards - which went down well with the fans!
"It wasn't malicious but he hurt his hand and stayed down for ages. I got booked, although Saint and Greavsie said I should have been sent off!
"I remember my goal well. Alan Devonshire had the ball and rolled it inside to me. I just whacked it low and hard and it bounced just in front of Gary Bailey and nestled in the corner.
"Tony Cottee then scored the winner and it was a result that really made us believe we could go on and push for the title."
Nowadays, Mark is working hard on securing a return to the game in a coaching or managerial capacity and still keeps in touch with many of his old team-mates.
"I've been out of football since leaving Altrincham last year and once you haven't been involved for a while, it is very hard to get back in," he admits.
"I've applied for a couple of managerial positions at non-league clubs recently and I'm hopeful of securing something for next season.
"I'm prepared to relocate - you have to go wherever the work is - and I still have a lot of friends in the London area.
"I'll be seeing a lot of the old players at a West Ham tribute dinner in April, so we'll catch up on old times and have a good laugh."