Fitton said: "We have made no secret of what we think his value is. I'm not surprised Celtic's interest is not going away, because Simon is a class player.
"We have had two approaches from clubs, but nothing in writing."
The agent of Jermaine Beckford has told Leeds United that the striker needs to be given an improved contract if he is tp stay at the club.
Beckford, 25, scored 34 times as the Yorkshire side finished fourth in League One this season, but a 2-1 aggregate defeat to Millwall in the play-off semi-finals ended their hopes of promotion.
His contract runs out next summer and his agent, Nick Rubery, suggested the forward needs to be offered a new deal to prevent him asking to leave.
"I'll be speaking to Leeds this week to discuss his position. He's got a year left on his contract and he needs to know where he stands," he told the Yorkshire Evening Post.
"I don't know what Leeds are thinking with regards to their future plans and what part he might play in them, but it's something I need to clarify.
"Jermaine's scored a lot of goals in League One and he obviously wants to test himself at a higher level, but he's very open to the idea of signing a new contract with Leeds. He's not looking to move on, but his situation needs sorting out."
The Gillingham midfielder Adam Millerr has declared himself fit and ready for the League Two play-off final against Shrewsbury Town on Saturday.Miller, 27, missed both legs of the semi-final victory over Rochdale due to an ankle problem, but is back in contention.
The Huddersfield Town manager Lee Clark has dismissed speculation linking him with a move to bring striker Pawel Abbott back to the club.Abbott, 27, is expected to leave the League Two club Darlington this summer as the Quakers cut costs after going into administration.
The MK Dons manager Roberto Di Matteo has released a number of players following his side's play-off semi-final loss to Scunthorpe.
Tore Andre Flo, Ali Gerba, Jemal Johnson, Alan Navarro, Flavien Belson and Nathan Abbey have all been told that they will not be offered new deals.