Celtic manager Ronny Deila has admitted there is interest in Parkhead defender Virgil van Dijk after sealing a deal to bring in Manchester United's Tyler Blackett on loan.
The Scottish champions unusually confirmed the 21-year-old had signed for the club during the first half of their 3-1 Premiership win over St Johnstone on Saturday.
Speculation that deal means Van Dijk is on his way out will only intensify following Celtic's elimination from the Champions League qualifiers to Malmo on Tuesday.
Southampton have been credited with a long-term interest in the Dutchman, although their manager Ronald Koeman has so far refused to discuss the player.
Van Dijk also did little to dampen talk he could be on his way after the 2-0 loss in Sweden which condemned them to the Europa League instead.
Celtic's win came courtesy of goals from Leigh Griffiths, Tom Rogic and Charlie Mulgrew after a Dedryck Boyata own goal had put St Johnstone in front.
A highlight for fans was the parading of Blackett - who will spend the rest of the season in Glasgow - on the pitch during the half-time interval.
Now it seems increasingly likely that Van Dijk will depart before the transfer window closes at 6pm on Tuesday night.
Deila said: "From a coach's perspective, we want to keep Virgil because he is a good player. There is interest in him, there has been more than one club interested."
On what Blackett would bring to his team, he added: "Quality. That is the most important thing as I have said many times.
"He is a good player, an up and coming young player. He can play centre-back or left-back so we will see.
"He has experience playing for Manchester United. He really wanted to come to Celtic and we wanted him as well so I think he is going to be a good signing."
Deila also confirmed his interest in Inverness midfielder Ryan Christie, last season's Scottish Football Writers' Young Player of the Year and a PFA Scotland contender for their equivalent prize.
It has been reported they could bid £500,000 for the 20-year-old and then loan him back to his current club for the rest of the season.
Deila said: "He's a young player, he has a bright future and it is something we want to get into Celtic.
"But nothing is done, we are having talks with Inverness. That (loan) is an option but we will see what we agree."
Deila was pleased with Celtic's win and continued: "It was an important game to get back to winning ways and I am proud of the team.
"We had a hard start when we went 1-0 down but showed character and confidence into the first half, created a lot of chances and should have scored more."