Kieran Tierney is to visit a specialist on Thursday in a bid to overcome his injury issues.
The Celtic left-back has been plagued with problems this season and has missed a large part of the campaign.
He missed 16 games between December and February due to a hip injury but the new problem isn't related to that.
Tierney limped off against Rangers last month and has been in and out of the team since.
The 21-year-old has been suffering from a pelvic injury and missed last weekend's 0-0 draw with Hibs at Easter Road.
Neil Lennon previously admitted the Scotland star could need surgery on the problem and he will find out more once he visits the specialist.
Leigh Griffiths undergoes fitness tests as Celtic striker steps up return bid
Lennon said: "Tierney is seeing a specialist today. He’s not trained."
Emilio Izaguirre filled in for him at Celtic during the 0-0 draw with Hibs and Jonny Hayes could also move cover if needed.
Callum McGregor played at left-back against Rangers in December.
It's also a blow for any incoming Scotland boss with the left back unlikely to be available for Euro 2020 qualifiers scheduled for June.
