The Serbia international was one of a host of big money additions in the North East last year, with the Magpies paying Anderlecht £13m to snap him up.
Mitrovic had a turbulent debut season on Tyneside, but despite having netted only nine goals across 34 league games, Benitez recently talked up the player’s role in his team for the coming Championship season, hailing him as “really important”.
However, reports claim that the Spaniard has had a change of heart and has decided that he cannot trust the hot-headed 21-year-old.
Mitrovic is currently serving a four-game ban for getting sent off in Newcastle’s final game of the 2015/16 season – his second red of the campaign – and his role at St James’ Park is in some doubt following Dwight Gayle’s arrival from Crystal Palace.
Benitez is understood to have elected to sell the Eastern European over the coming weeks, and given that he has long been talked about as one of the most talented young strikers in Europe, it’s unlikely the Toon will be short of willing suitors.