Michael Owen has insisted that Stoke City goalkeeper Jack Butland is a good enough replacement for David de Gea at Manchester United.
The 22-year-old England international was able to keep a clean sheet in his side's 2-0 victory over Manchester City, as Marko Arnautovic's early brace overcome the league leaders.
De Gea is being linked with a move to Real Madrid after coming close to completing a move to the Santiago Bernbeu in the summer, leaving questions over who his replacement would be if the Spaniard were to make the move.
"Joe Hart is certainly looking over his shoulder now," Owen told BT Sport.
"For the last few seasons for England, he hasn't had too much pressure on him. But this lad Butland, I'm a huge fan of his. He is a monster of a lad, brilliant with his feet and top class with his hands as well.
"I think he can go on to become the England goalkeeper of the future. I think if someone like Manchester United, if David de Gea leaves, or Liverpool if they aren't happy with Mignolet - I think one of those two clubs could come calling soon because he is that good."
De Gea also kept a clean sheet in this Saturday's round of fixtures, as the Red Devils played out a stalemate with West Ham United.