The 18-year-old started the Red Devils’ 1-0 win over Manchester City in the EFL Cup last night at Old Trafford.
However, he was replaced eight minutes from time by Jesse Lingard and he appeared to clutch his thigh.
And after coming off, he headed straight down the tunnel instead of sitting on the bench.
Manchester United and Manchester City combined XI
Wed, October 26, 2016Express Sport has picked an XI made from the cream of both Manchester sides ahead of tonight's EFL Cup clash at Old Trafford (8pm)
Express Sport runs through our best possible combined XI from players that could feature in tonight’s Manchester derby, although it is more than likely plenty of young guns will actually get the nod in the EFL Cup clash
According to the Manchester Evening News, United’s medical staff will check out Rashford today.
However, it is unclear the extent of the striker’s injury just yet.
The treatment table is mounting, with Eric Bailly, Chris Smalling, Wayne Rooney and Anthony Martial all missing the game through injury.
Bailly represents United’s biggest blow, as he will be out for up to two months.
United will be looking for their first Premier League win in four games against the Clarets on Saturday (3pm).