Celtic star Boli Bolingoli is a major doubt for Sunday’s cup final against Rangers amid frustration in his recovery, Football Insider understands.

The 24-year-old is being assessed by the club’s medical staff ahead of Sunday’s showdown at Hampden Park after being sidelined for more than a month with a hamstring injury.

A Celtic source has told Football Insider that the club’s coaches are preparing to be without their first choice left-back in the Scottish League Cup final.

He will undergo a late fitness test and be given as much time as possible to feature, but Neil Lennon and his staff fear Bolingoli is likely to miss out as he makes slow progress in his rehabilitation.

He was pictured back in training yesterday but Lennon ruled him out of tonight’s Scottish Premiership clash against Hamilton Academical.

It will be the fifth consecutive league match missed by Bolingoli, who last featured in the League Cup win over Hibernian on 2 November.

He posted a message on his social media earlier this week of a glass half-full symbol alongside an image of him in action.

But Celtic are wary of rushing Bolingoli back for such a physically and mentally draining fixture as an Old Firm derby.

Lennon will not be able to call upon Greg Taylor against Rangers, as he is cup-tied following his protracted summer move from Kilmarnock.

Should Bolingoli miss out, the manager could call upon Jonny Hayes as he is deemed closer to making a return to full fitness after a shoulder injury.

In other Celtic news, it can be REVEALED that the club have landed a sensational £15million windfall…and there’s more cash heading to Parkhead.