Virgil van Dijk says he is pondering his Celtic future after the Champions League play-off loss to Malmo.
The Dutchman heads a shortlist of four defenders who Southampton are interested in and the clubs held talks about a potential transfer this summer.
"Celtic is an amazing club and I'm very thankful for everything," said the 24-year-old following the 4-3 aggregate defeat by the Swedes.
"But if the right opportunity comes then I'll consider it."
Van Dijk moved to the Glasgow club for £2.6m from Groningen in June 2013 on a four-year deal.
"It's a terrible way [to go] if it ends like this but I have a lot of great memories at the club," he added.
On the eve of a disappointing exit in Malmo, manager Ronny Deila said he was "tired of talking about him" adding that van Dijk "is still a Celtic player and hopefully he'll be that for a long, long time".
After the 2-0 defeat at the Swedbank Stadium, the Celtic boss explained: "We don't have to sell him. But you never know what happens in football.
"He is under contract with us, he is a very good football player and a football player we want to keep."
Quizzed about the link with Southampton, Van Dijk replied: "I think you need to ask the board.
"I don't know what will happen in the coming days. I've not been talking to anyone. Now that qualification is over we will wait and see.
"I'm not looking for anything. It's a great place to be and they gave me an opportunity to show myself, so I'm very thankful for that."
|BBC Scotland's Tom English:|
|"Every time Celtic miss out on the Champions League group stage they make it harder on themselves to return. You really have to wonder when Celtic will be back on the big stage."|
The Dutchman apologised to fans after a tame loss to Malmo, with Celtic having led 2-0 just 10 minutes into the first leg.
"We knew there was pressure before the game and we told each other to be calm, take your moments and just play our game because we are better than them but we didn't show it.
"They got the belief after the first goal, which was a foul in my opinion. After that, we had trouble keeping the ball and simple things went wrong.
"I'm a winner. I want to win every game I play. But we were poor and there is no excuse."