Everton manager Roberto Martinez has claimed that not even a "huge" transfer offer can persuade the club to sell Ross Barkley this summer.

Barkley's displays for the Toffees in the Premier League this season earned him a spot in England's World Cup squad, but Martinez insists that seeing the midfielder's stock rise does not mean that his departure is a possibility in the transfer window.

"I would not sell even if we got a huge bid. It would be wrong for him," the Spaniard told reporters. "I always feel as manager you develop a relationship with players and you're always honest with that.

"Ross is a phenomenal talent, probably the best English talent I have ever seen, but he is not the finished article yet and you need to be very careful.

"It's our duty to protect him and I know Everton is the perfect place for him for the next 12 months."

Barkley has been tipped to shine in Brazil by Everton and England teammate Phil Jagielka.