John Kennedy labelled Norway manager Stale Solbakken 'disrespectful' after the latter urged Kristoffer Ajer to leave Celtic.
During the international break, Solbakken warned Ajer that the Scottish Premiership wasn't 'challenging' enough for him and said that the centre-back would be 'smart' to seek a move to one of Europe's top five leagues.
Kennedy: Ajer is already playing for a 'massive club'
Celtic's interim boss Kennedy struck back at the weekend in response to Solbakken's advice to the Hoops defender.
"We are a massive club in our own right who compete in Europe every season," said Kennedy (via Daily Record).
"There's no doubt there will be interest in Kris because of his profile, his age and where he is at. But I found the statement and the comments disrespectful towards ourselves."
Could Ajer leave Celtic this summer?
The 22-year-old defender is about to enter the final year of his £14,000-per-week Celtic contract, and the Daily Mail reported in recent days that Newcastle had set their sights on Ajer and were preparing an £8m transfer offer.
Celtic signed Ajer as a 17-year-old from Norwegian club IK Start in 2016. He has gone to rack up 171 appearances in green and white, as well as earning 21 caps for his country (via Transfermarkt).
This season, Ajer is averaging 3.2 successful aerial duels, 88.2% passing accuracy, 1.3 tackles, 1.4 interceptions and 3.4 clearances per match (via WhoScored).
Transfer Tavern verdict
Kennedy is justified in calling out Solbakken, who should have raised his concerns with Ajer privately. The defender may only be 22 but his national team coach is clearly itching for him to make the next step.
Celtic, for their part, may try to commit him to another two or three years in Glasgow before a lucrative sale.
The increasing prospect of working with Eddie Howe may be persuasive, and losing him for less than £10m would have to be regarded as a real disappointment.
In other news, a Premier League offer could also arrive for this Celtic midfielder.