Wigan Athletic have made a £3.5 million offer for Middlesbrough midfielder Lee Cattermole.
Cattermole was not involved in Boro's friendly with Celtic on Tuesday evening, which some saw as an indication of his likely departure.
Boro boss Gareth Southgate has already stated he would not stand in Cattermole's way as he cannot guarantee the England Under-21 international first-team football.
"We've had a revised offer from Wigan and we felt that he was probably not in the right frame of mind to play [against Celtic]," said Southgate.
"It's not a done deal but the offer gives us something to consider and we thought for all parties it was best for him not to play.
"It's not agreed, but it's pretty close to what we're looking for. He's still our player and with us on the trip but something could happen in the next 24 hours."