Pompey’s battle against the drop has been dealt a blow after George Thorne was ruled out for the rest of the season.
The midfielder, on loan from West Brom, left Fratton Park on crutches after suffering an injury to his left ankle during Saturday’s 5-1 loss to Burnley.
Blues boss Michael Appleton had been optimistic Thorne’s injury was not serious.
But the 19-year-old will now play no further part in Pompey’s fight for Championship survival.
Appleton said: ‘There’s no chance of him (Thorne) playing again this season.
‘It’s a blow. He’s been outstanding.’
After returning to the club for a second loan spell in February, Thorne initially took time to find his feet but had been in fine form before his injury last weekend.
Pompey will not be allowed to bring in another loanee to replace Thorne as the emergency loan window is now closed.