The young forward limped out of the Glovers’ 4-2 win against Reading Under-23s on Tuesday with an ankle problem.
Khan has been a regular in Darren Way’s side this season, featuring on 32 occasions in all competitions.
“At the moment we’re in doubt (about his fitness),” Way told YTFC.net.
“We’re not too sure but hopefully he’ll be assessed this afternoon and we’ll have to make that decision later on.”
The Glovers could have defender Darren Ward back for their visit to Adams Park.
The 38-year-old has missed the last seven weeks of the campaign with a knee injury but has returned to full training.
“Wardy is back in training now and I’m looking forward to having him back,” Way said.
“He’ll play a massive part in the second half of the season.
“He’s someone who carries himself very well around the training ground and the players look up to him so it’s good to have him back.
“He’s been training very well so I’ll make the call (about selecting him) when it needs to be made.”
Swansea City loanee Ryan Hedges (ankle) is the Glovers only confirmed absentee after he was ruled out for up to six weeks.