CHARLIE Mulgrew, whose contract with Celtic is set to expire in the summer, will have to prove his fitness to manager Ronny Deila before he is offered a new deal by the Parkhead club.

Mulgrew has been sidelined since the start of December when he suffered a recurrence of the hamstring tendon problem which kept him out for six months last season in the Europa League game against Ajax at Celtic Park.

The 29-year Scotland internationalist is expected to be available for selection again next month and Deila is keen for the versatile player, who can be deployed in a number of positions both in defence and midfield, to be back involved.

However, the Norwegian, who this week signed Danish defender Erik Sviatchenko and who is looking at Croatian midfielder Ljuban Crepulja on trial, wants the player to show he has overcome his injury problems.

Deila confirmed contract negotiations were continuing with first team regulars James Forrest, Stefan Johansen – who was this week linked with a move for bottom-placed Premier League club Aston Villa – Mulgrew and Tom Rogic.

Asked about Forrest, Deila said: “We are going to meet this month and things are going forward. I don’t have any doubt he wants to stay, but you never know what options a player has.

“That goes for every player, you can’t have full certainty until the contract is signed. Rogic is still going on as well, hopefully we can get a deal done. Stefan is another. His contract is longer but he is a player we want to keep. Charlie is also in that category.

“The most important thing is getting Charlie injury free and then we will see what’s happening. He will be thinking the same. He wants to get back in to top shape to be as good as he can be.”

Deila stressed that Celtic were just looking at Crepulja, a 22-year-old creative midfielder, despite his club Slaven Belupo claiming the Scottish champions had tabled an offer of £300,000.

“He is here for some days to get to know us and for us to get to know him,” he said. “There is nothing more than that. We will see if he is the quality we are looking for. The club knows what they can get if something happens.”

Meanwhile, Deila stressed Celtic were keen to hold onto Johansen and had no interest in Rangers signing target Michael O’Halloran of St. Johnstone. He said: “We want to keep Stefan, that is how it is. We know all about O’Halloran. We don’t feel like is the right moment to go in that direction.”