Kilmarnock manager Jim Jefferies has accused Celtic of being discourteous to Steven Naismith by not following up an alleged £2m offer for the striker.
Steven Naismith has become frustrated by the transfer saga
Jefferies claims Celtic verbally agreed to meet Killie's valuation on Monday.
But Jefferies said: "What is a little bit concerning is that we haven't heard anything yet.
"They might be busy or have other things on. But if they ask to speak to him then it's only courtesy to the player that they speak to him quickly."
Celtic had wanted assurances that Naismith wanted a move to the Scottish champions before a fee was agreed.
And sources at Celtic Park have insisted that they have not yet put in a firm offer.
The 21-year-old, who scored 19 goals for Kilmarnock last season, had said perviously that he would prefer to join Rangers, the club he supported as a boy.
We have agreed the fee with Celtic, which is why we gave them permission
Kilmarnock manager Jim Jefferies
But Kilmarnock have turned down four bids from Rangers for Naismith and manager Walter Smith has said he has withdrawn his interest in the player.
The Scotland international submitted a written transfer request last week after becoming frustrated with the long-running transfer saga.
Hearts and Hibernian are also believed to have made contact with Kilmarnock about the player.
But it is Celtic who are the latest to have talked to Killie chairman Michael Johnston and the first to agree to meet their £2m valuation.
"I've kept Steven up to date with everything, but it has caused a lot of anxiety for him and it's not fair," said Jefferies.
"Steven intimated that he would be willing to speak to Celtic because there is no point in wasting everybody's time.
"And, after giving them permission, we would like to find out what they are doing."
Jefferies is not resigning himself to the SPFA Young Player of the Year joining the Scottish champions if and when they do get round the table.
"His talks with Gordon Strachan will determine whether he goes there or not," said Jefferies.
"They will only find out if they can convince him to go there, or if they like what they see in Steven, if they speak to him.
"The fee has never changed from day one.
"Some people can choose where they want to go when they are out of contract. But, while they are in contract, the two clubs need to agree a fee.
"We have agreed the fee with Celtic, which is why we gave them permission.
"One thing that it has never done is affect his training. That's why I have never had any problems playing him in the first team."