West Ham United, West Bromwich Albion and Everton are already interested as he could be sold for a fee of around £15million this summer.
The Portuguese boss has decided to replace him with Sweden’s Victor Lindelof as he believes Smalling is not good enough to have a role in his team, as he holds reservations over his mental toughness.
He missed six weeks of the season after suffering a broken toe in a Europa League win over Fenerbahce in October and Mourinho reacted to the situation by questioning the defender’s desire to play through the pain barrier.
Smalling has recently switched agents and reports claim it’s a move to help him get the best move at West Ham, West Brom or Everton.
West Brom and Everton are both in the market for a centre-back this summer and are watching Smalling’s situation carefully, as he could be offered a return to London with West Ham.
He was voted Players’ Player of the Year for United at the end of former manager Louis van Gaal’s final season in charge, but he just hasn’t been the same player and has fallen further down the pecking order.