Roberto Martinez has defended the decision to sell Lee Cattermole to Sunderland.

Although Wigan Athletic have spent much of the summer insisting the midfielder is not for sale, the player has joined the Black Cats for an initial £6million which could raise to £8million.

Steve Bruce will no doubt be delighted to land Cattermole, his number one target this summer, and Martinez has defended the decision to let the England Under-21 international make the move.

"The fee is a good one, it is far more than the club paid for him last year and the third highest in Wigan Athletic history," he told Wigan's official website. “Sunderland have now matched our valuation.

"It became clear over the past days having spoken to Lee that he wanted to leave and it is very disruptive to the group when a player is clearly unhappy. My number one priority has to be the club.

“It left me with a decision to make, I therefore agreed to the move for the good of the players we have at the club and who want to remain with us and help us progress to the next level."