Stanislav Varga could perform a surprise U-turn and remain at Celtic next season.
The 33-year-old defender's contract expires next month and he looked certain to leave Parkhead after more than three years at the club.
He fell out of favour with manager Gordon Strachan earlier in the season, prompting his agent, Tony McGill, to claim that Rangers chairman David Murray had a better chance of being offered a new deal at Celtic than Varga.
However, the Slovakia international was recalled to the top team for the last six games of the season and those performances could win him a new deal.
Reports today suggest Celtic are ready to table a one-year contract extension and McGill has now refused to rule out the possibility of Varga remaining at the club.
He said: 'We are speaking to a number of clubs at the moment and it's too early in the day to say much yet.
'There is still a long way to go. We are not ruling Celtic in or out.'
However, Celtic could face a battle for his signature with his agent claiming he is attracting interest elsewhere.
Varga was a target of Hibernian earlier in the season and Tony Mowbray could renew his interest, with Gary Caldwell moving to Celtic.
He has also been linked with a number of Championship clubs in England and McGill added: 'We have four offers at the moment.'
Meanwhile, Charlie Mulgrew is determined to make the breakthrough at Celtic next season.
The 20-year old defender has returned to the east end of Glasgow following a successful five-month loan spell at Dundee United, where he picked up a Young Player of the Month award.
Now he has his sights set on the Celtic top team.
He said: 'I'll speak to the gaffer over the summer and I know I'll need to work hard in pre-season if I want to force my way into the team.
'But, with Shaun Maloney, Stephen McManus and Mark Wilson all regulars last season, the manager has shown that he is willing to give young Scottish boys a chance.
'That's very encouraging for me and everyone coming through at Celtic.'
United finished a disappointing ninth in the Bank of Scotland Premier League but Mulgrew believes he has benefited from his time at Tannadice.
He told the club's official website: 'Going to United was a great experience.
'You're playing in front of big crowds and against better players, and there are different pressures involved compared to under-19 or reserve football.
'It's helped me mature as a player and I would recommend going out on loan to any of the young boys at Celtic.
'I think moving to United improved my all-round game and I feel I'm mentally prepared to play at that level now.
'My concentration and fitness is also better and I've definitely gained from the experience.'