Bulls defender Ryan Valentine is expected to miss the remainder of the season.
The former Wrexham and Darlington man was originally reported to have a 'stomach problem' that caused him to miss the FA Cup Round One match with Hythe. Later it was reported as a hip injury but diagnosis has been tricky and the problem is believed to be related to the pelvis, although no official confirmation has been forthcoming.
Rob Purdie had a similar problem that saw him miss the entirety of last season with Oldham. It took the Latics several months to diagnose his problem, as is common with this type of injury, and send him for surgery that ended his season.
Without Valentine the Bulls will have to decide whether to seek a lengthier stay for Joe Heath, who has filled in for eight of the eleven games Valentine has missed, or seek an alternative replacement.
The former Man Utd and Nottm Forest trainee has indicated a willingness to remain with the Bulls and, with his Exeter deal expiring in the summer, he may be open to follow Nicky Featherstone in committing to a permanent deal at Edgar Street.
Meanwhile former Bulls defender Garry Breen has swapped south for north, moving from Ian Foster's Dundalk to Northern Irish strugglers Portadown. The Eire u21 international struggled to get into the Airtricity League side's team during the latter stages of last season and was not offered a contract for the next season that starts next month.
The County Armagh side are currently three points clear of the bottom two in the Carling Premiership, with the bottom side automatically relegated and the second bottom side facing a play-off to avoid the drop.