Ronald Koeman claims Southampton would not sell Sadio Mane in the January transfer window, even if they were offered £100million.
Mane was the subject of interest from Louis van Gaal's Manchester United towards the end of the close-season window and the south-coast club are bracing themselves for further advances.
Asked if he would consider selling any of his players next month, the Koeman replied: "No, no, not in January. Already we spoke about that situation. We sell nobody in January.
"Nobody - not even if they pay £100m."
Mane impressed in his debut Premier League campaign last season, netting the division's fastest-ever hat-trick (two minutes, 56 seconds) against Aston Villa.
"I think he can still improve in some cleverness to know what his position is on the pitch, both inside and outside," he said.
"I think still he can be more dangerous if he knows exactly the moment to have that movement in the space behind the defenders.
"In front of the goal he can be more of a scoring player but he is young - 23 years old - and a great player. It is a pleasure to work with him."
