Oxford United are waiting to discover the extent of the injury suffered by Jon Meades against Coventry at the weekend.
Meades fell to the ground unchallenged during the second half of the U's 1-0 win over the Sky Blues on Saturday and was carried off on a stretcher with his left leg in a brace.
The summer signing was taken straight to hospital for an X-ray, which revealed there was no break, but the club are now awaiting the results of an MRI scan to see if the 21-year-old defender suffered any ligament damage.
"You understand, especially with a brave boy like he is, when they stick their hand up straight away there's a problem," manager Chris Wilder told the Oxford Mail.
"He caught his studs in the turf and just fell awkwardly. No-one was near him and there's no blame on anybody.
"Hopefully it will be okay but it took the gloss off what had been another excellent afternoon for us."