Neil Lennon acknowledges that Georgios Samaras has a big decision to make at Celtic, but expects a call to be made shortly.
The Greece forward, who has become something of a Parkhead cult hero, will see his current contract expire at the end of the season.
Celtic have expressed a willingness to prolong his five-year stay in Glasgow, but appreciate that he may decide to take on a new challenge.
At the age of 28, the former Manchester City forward should be reaching his peak, in a World Cup year, and reports suggest he may be given the option to head back to England in January.
Lennon hopes Samaras will agree to stay put, saving him time and money in the transfer market, and hopes the issue will be resolved one way or another inside the next seven days.
He told the Daily Record: "It's not money, it's never been top of his agenda. It's where he sees himself playing for the next three or four years.
"We can't do anything about a competitive league but we can give him the European experience and those nights at Parkhead are difficult to find elsewhere.
"He could have gone before he signed his last contract and earned much more money, and he didn't.
"He loves the club and he loves the city, but there are mitigating factors as to why he hasn't signed and why we haven't come to a deal.
"He's an intelligent boy. He does think deeply and he is very knowledgeable about the game.
"He has vast international experience with Greece and losing a player such as him would be a real blow to us. He'd be hard to replace and I can see why there are clubs interested in him.
"If he does go - and we'll probably know in the next week - we will need to work hard to find a like-for-like replacement, and these types cost a lot of money."