Mateta has caught the eye with his performances for Mainz this season, with the 23-year-old scoring seven times in the Bundesliga and three times in the German Cup.
He struck twice against Borussia Monchengladbach in October and grabbed a hat-trick against Freiburg in November.
The Frenchman could be the subject of bids during this month’s transfer window and has been strongly linked with Premier League side Leeds.
Mainz sporting director Heidel is clear though that the club are not looking to sell the striker.
“It is not our plan to sell Mateta at all at the moment”, he told Sky Deutschland.
However, Heidel added: “Anyone who knows me knows that I never say a player is not for sale.”
The ball may be in the court of Mateta’s suitors to slap in a bid which is so tempting Mainz cannot refuse it.
Mateta, who has turned out for France up to Under-21 level, is under contract at Mainz until the summer of 2023.
