Portsmouth manager Andy Awford says Jack Whatmough is "likely" to miss the rest of the season with a knee injury.
Defender Whatmough, 18, suffered the injury in the 2-2 draw with Cheltenham and Awford confirmed ligament damage.
"He's had his scan, there is ligament damage which we suspected," Awford told BBC Radio Solent. "He will certainly be out for a little while."
When asked if he would be absent for the remainder of the season, Awford replied: "It's likely."
The Pompey boss added that the club are awaiting the full results of the scan to determine the severity of the problem.
Whatmough has been a key player for Pompey this season, playing 24 times for the club, and Awford says they will look to bring someone in on loan as cover.
"He's been very good all season whenever he has played," said Awford. "He's had a fantastic season and it's a huge blow for him.
"We've got irons in fires and we'll look to do something before the weekend."