One of the Hoops' standout performers this season has been German winger Kuhn, who has already scored 10 goals and registered 11 assists in 17 appearances for Brendan Rodgers's side in all competitions.
Kuhn scored twice in Celtic's impressive 3-1 comeback victory over RB Leipzig in the Champions League, shortly before scoring and assisting in the Hoops' 2-0 win against Kilmarnock in the Scottish Premiership last weekend.
The 24-year-old's strong start to the campaign has subsequently caught the eye of several European clubs, with Sky Deutschland reporter Florian Plettenberg claiming that Premier League duo Fulham and Brentford have made enquiries for the winger and continue to monitor his situation.
Kuhn only joined Celtic from Rapid Vienna for just £3m in January and it is thought that the Hoops will not let him leave on the cheap, considering his importance under Rodgers and the fact that he still has over four years left to run on his contract.
Kuhn out, Kvistgaarden in at Celtic?
However, should Celtic receive an acceptable offer for Kuhn in the near future, the Glaswegian giants may look to step up their pursuit of in-demand forward Kvistgaarden - not a like-for-like replacement for Kuhn, but someone who has been on the club's radar for some time.
The Scottish Sun reports that Celtic have reignited their interest in Kvistgaarden after they were heavily linked with the Brondby frontman in the last two transfer windows.
Tipsbladet, meanwhile, claims that 'big' European clubs including Celtic, Brighton & Hove Albion, Fenerbahce, Feyenoord, Bologna and Hellas Verona all sent scouts to watch Kvistgaarden in action as Brondby drew 1-1 with Nordsjaelland last weekend.
The 22-year-old, who is said to be valued at around £8.5m, scored 10 goals in 28 appearances for Brondby last season, but he has since bettered that this term by netting 13 times in 20 games across all competitions, including a strike in the aforementioned draw with Nordsjaelland.
Celtic-linked Kvistgaarden addresses transfer rumours
Kvistgaarden, predominantly a centre-forward who can also operate on either flank, has a contract with Brondby until June 2027, but he has refused to rule out the prospect of leaving the club in the near future.
Speaking to Danish news outlet Bold about a possible January move to a bigger European club, Kvistgaarden said: "It would be great if a lot of things came from outside. You dream of leaving at some point.
"There are still games left, and if that were to happen, then you know that you are standing and suddenly you have the last few games in the Brondby shirt this time around.
"So right now I'm just looking towards the next game and enjoying every single second I wear this shirt."
While Brondby currently sit sixth in the Danish SuperLiga and only four points adrift of the summit, Celtic sit joint-top of the Scottish Premiership along with Aberdeen after winning 10 and drawing one of their opening 11 games.