The 27-year-old is widely expected to leave Chelsea this summer after falling out of favour and losing form under Maresca.
French outlet L'Equipe recently reported that Man United were interested in bringing him to Old Trafford as they seek to bolster their attack following their worst ever Premier League season.
The report adds that Ruben Amorim’s side have already held talks with Nkunku’s representatives, although no concrete offer has been made.
Speaking ahead of their FIFA Club World Cup game against Espérance Tunis, Maresca addressed the rumours.
The Italian said: "Christo is with us. He's our player. He's doing very well in the last four, five days. For sure, tomorrow we are going to do rotation. We'll see if there is any chance for the ones that are not playing a lot."