Celtic midfielder David Turnbull could return from injury for the crucial weekend meeting with Rangers, according to ex-Hoops striker Frank McAvennie.

The Lowdown: Hoops face season-defining game

The biggest game of the Scottish Premiership season takes place on Sunday lunchtime, as Ange Postecoglou's side head to Ibrox to face Rangers.

Celtic are currently three points clear of their bitter rivals at the top of the table, so the importance of the result this weekend is undeniably huge.

Victory for the Hoops would put them in pole position to wrestle back their league crown, although defeat would blow the race even more wide open.

The Latest: Pundit makes Turnbull claim

Turnbull has only featured for Celtic one since December because of a hamstring injury, but speaking to Football Insider, McAvennie claimed that the 22-year-old could feature at Ibrox:

"Turnbull is coming back but we don’t know how fit he is. Is he fit enough to play 90 minutes in an Old Firm? I guarantee you he will certainly be asking to play.

"Everyone wants to play and Ange knows how good Turnbull is on his day.  I think he could play some part, maybe he won’t be risked because we have a tough end to the season and we need everyone fit.

"So maybe he could play half an hour or something like that. I’ve missed watching him because I’m a huge fan of his. Ange will want him back playing so I think he will want to give him some minutes.

"It would be wonderful to see him back because he is a magnificent player."

The Verdict: Potential huge boost

This could be a massive boost for Celtic, with Turnbull clearly a special talent who has the ability to unlock a defence or produce a piece of magic on his own.

The Scot has scored five goals and registered four assists in the league already this season, not to mention one and two in the Europa League, respectively.

It may be that Postecoglou feels Turnbull isn't ready to start against Rangers but he is someone Giovanni van Bronckhorst could fear coming off the substitutes' bench.

In other news, Celtic are expected to sign one player this summer. Find out who it is here.