Celtic are poised to fight Fulham moves to snatch central defender Dedryck Boyata.
The London club have had a £9million bid to sign the Belgian World Cup star rejected, but are prepared to increase it to £12m as they prepare for life back in the English Premier League.
Celtic have said he is not for sale but Boyata is keen on the move.
Fulham are desperate to sign Celtic centre-back and Belgian World Cup star Dedryck Boyata
Entering the final year of his current deal, Boyata is keen to capitalise on a strong World Cup campaign in Russia after stalling on a new contract with Celtic.
However, Sportsmail understands the Parkhead club are highly reluctant to sell the 27-year-old as they prepare for a Champions League third round qualifier with AEK Athens.
Fulham boss Slavisa Jokanovic is expected to step up efforts to land Boyata before the English transfer window closes on Thursday.
The club have spent £15m on Swansea defender Alfie Mawson, but he is not likely to be ft until September.
Forced to go with the inexperienced pairing of Jack Hendry and Kristoffer Ajer against Rosenborg, however, the Premiership champions have not yet given up hope of persuading the former Manchester City defender to sign a new deal.
Speaking at the launch of Celtic's new third kit yesterday, Norwegian defender Ajer said: 'Dedryck Boyata is a top professional who always keeps fit.
'He was obviously very happy with Belgium's World Cup achievements. It was great for them and it was good to see.
'Dedryck and other experienced centre-halves have helped my development a lot since I broke into the team.
'We played a lot together last season and he was fantastic at communicating with me throughout the games. He's been really helpful.
'So, of course, I would like to see him stay. He's been fantastic at Celtic, which is a club that has a lot of fantastic players. I would like to keep playing beside him and keep learning from him.
'At Celtic, there is competition in every area of the pitch. But that is healthy because it pushes you hard in training every day and you have to be performing well in every game.'
Fulham boss Slavisa Jokanovic wants defensive reinforcements before the new season
Celtic, meantime, have been handed a favourable chance of reaching the Champions League group stage for a third consecutive season - if they can beat AEK Athens in the third qualifying round.
Yesterday's draw for the play-off round paired the winners of Celtic's tie with Swedish side Malmo or Hungarian club MOL Vidi.
Malmo currently sit sixth in the Swedish league after 16 games while Vidi sit fifth in the Hungarian league.
The draw could have been significantly worse for the Scottish champions, who avoided PSV Eindhoven, Red Star Belgrade, and Dinamo Zagreb as well as the prospect of a nightmare journey to Azerbaijan to face Qarabag or Kazakhstan to take on Astana.