Lazio president Claudio Lotito has insisted that Sergej Milinkovic-Savic would cost "much more" than €50m (£42.3m) during this summer's transfer window.
The Serbia international's future is currently being called into question, with Manchester United believed to be considering a move for the central midfielder over the next couple of weeks.
There had been claims that the Red Devils could sign the 27-year-old for little over £40m this summer, but Lazio's president has sent a transfer warning to the 20-time English champions.
"Milinkovic for €50m (£42.3m)? At that amount, I don't sell him, he is worth much more," Lotito told Il Messagero. "Our market is thus complete and finished.
"Also, because Luis Alberto will also remain. I quickly kept all the promises I had made. All the reinforcements [manager Maurizio] Sarri wanted on the sheet have been taken."
The midfielder was again in impressive form for Lazio during the 2021-22 campaign, scoring 11 goals and registering 12 assists in 47 appearances in all competitions.
Milinkovic-Savic only has little over two years left to run on his contract in Rome, though, and there has been a host of speculation surrounding his future this summer.
"Milinkovic is not for sale. I turned down €140m (£120m) bid for him [years ago]", Lotito recently told Rai Sport when questioned on the Serbian. "I'd ask Sergej what he wants to do only in case we receive an important proposal from a world-class top club."
The midfielder has scored 58 goals and contributed 51 assists in 294 appearances for the Italian club since arriving from Genk in August 2015.
A recent report claimed that Man United would be prepared to pay €68m (£57.5m) for Milinkovic-Savic but that would allegedly still be short of the Serie A side's asking price.
Man United have added Christian Eriksen to their midfield this summer, but Paul Pogba and Nemanja Matic both left the club on free transfers over the summer.
Juventus' Adrien Rabiot has also been strongly linked with a move to Old Trafford, while the Red Devils are still said to be keen on signing Frenkie de Jong from Barcelona.
Rabiot, De Jong and Milinkovic-Savic are not expected to all arrive, so a bid for the Lazio midfielder could seemingly depend on whether Man United give up on their pursuit of De Jong.
Erik ten Hag's side are also expected to bring a new forward to the club before the end of the transfer window despite seemingly winning their battle to keep hold of Cristiano Ronaldo. body check tags ::