Nadir Ciftci's agent says the Turkish striker would consider a move to Celtic, but they would need to meet Dundee United's £1.5m asking price.
The 23-year-old has already rejected a move to Wigan Athletic, who had a bid of that amount accepted by United.
And agent Pierre van Hooijdonk told BBC Scotland: "There are only two offers on the table at the moment from two clubs.
"He told Wigan he does not want to go there. If United accept an offer from Celtic, we could talk."
Celtic have already had two offers of £900,000 and £1m rejected for the player who joined United from Breda in 2013.
However, former Celtic and Netherlands striker Van Hooijdonk insists that Ciftci is happy working under United manager Jackie McNamara.
"We don't want to put the player in a situation that he doesn't want to be in," he said. "He is not desperate to go.
"Nadir is away with United to Holland next week. He is very comfortable in this situation. He is not panicking because of the situation.
"When the offer is right for United and for the player, he will listen to the offer. If it's not, he won't be forced to move."
United suffered serious criticism from supporters after the sale of midfielders Gary Mackay-Steven and Stuart Armstrong to Celtic in January, with many fans feeling that the pair had been sold too cheaply to a major rival.
Now it appears that United chairman Stephen Thompson is digging his heels in over the striker, who played for the Netherlands and Turkey at youth level, previously played for Kayserispor and Portsmouth and scored 16 goals from 42 appearances last season.
He told BBC Scotland that, since Celtic's second offer had been rejected, there had been no further bids from them.
"There is nothing to report," he said. "Really, until someone offers the right price, he is a Dundee United player and under contract - end of story."
Asked about Ciftci on Saturday, Celtic manager Ronny Deila refused to divulge any details on his pursuit of the striker.
"I can't comment on anything before we have anything ready," he said.
"We have different players we work with and we'll see what we can get arranged."