After the winter break in Dubai Brendan Rodgers opted to go with Scott Bain as his first choice keeper with Gordon still to play any football this year.
The former Sunderland keeper threw himself into extra training to retain his sharpness but is now paying the price with concerns over a knee condition.
Dorus de Vries was on the bench against Aberdeen last week with Lennon explaining the situation with the keeper who finished 2018 as Celtic’s first choice.
“He has a bit of a knee problem,” Lennon revealed. “He had an injection on it and it’s not really settled, he will be assessed by a specialist over the next couple of days so hopefully we can come to some sort of impasse.
“He may need another injection just to settle everything down to get him back to training and playing. It’s just been a little bit of over use for him,. When he has been playing he’s been able to rest, he’s not been playing so he has been training a lot more and an old problem has flared up.”
With Ross Doohan and Conor Hazard out on loan at Ayr United and Partick Thistle, Ryan Mullen is the next keeper in line after de Vries.
After his promotion to first choice keeper at Celtic Scott Bain is expected to become first choice keeper for Scotland, making his competitive debut away to Kazakhstan.