The Red Devils head into the game looking to return to winning ways after the disappointment of their 1-0 loss to Southampton at Old Trafford in the Premier League last weekend.
Louis van Gaal has found himself under intense pressure in recent weeks following his side’s poor run of form.
United have only won two of their last 10 Premier League games and are currently five points adrift of the top four heading into the final 15 matches of the season.
However, former Everton man Gray is expecting to see United secure their progress to the fifth round of the FA Cup on Friday night.
Gray wrote on his blog for Paddy Power: “This is a great opportunity for Derby. They’ve been yo-yoing form wise though, lost their last two conceding seven goals.
“It’s your best chance for an upset around the grounds this weekend though.
“I think Van Gaal will go in strong as they’ve an extra day’s rest ahead of the midweek game. Andy’s bet: Man United 1-0.”
United finished fourth in Van Gaal’s first season in charge of the club last term.
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