The Everton manager Roberto Martínez has given a clear indication to Manchester United that he intends to fight to keep the England defender Leighton Baines.

The club last week turned down a £12m bid for the left-back as the former Everton manager David Moyes returned to his old club in an attempt to cherry-pick one of their prized assets.

While that offer was rebuffed United are expected to come back with a significantly improved figure but Everton have stressed that Baines is not for sale and want the 28-year-old to extend his contract beyond the existing two years he has left.

Martínez underlined the England international's importance to the club. "I think Leighton is more than a player, he is an icon," he told the Liverpool Echo.

"He represents a lot about our football club and I am really, really excited about Leighton.

"This is a big season for him and for us as a club. When you are the left-back of this football club, and the level that he has been reaching over the last few years consistently, it shows me that he is the best left-back in the country. I can't wait to start working with him."

Martínez, appointed as Moyes' successor last month, was meeting his players for the first time on Wednesday as they returned for pre-season training.

He hopes to be able to add to his squad in the coming days; it is understood deals for his former Wigan players Arouna Koné and Antolín Alcaraz are almost completed.

The striker Koné is likely to cost Everton £6.5m but the centre-back Alcaraz will arrive on a free transfer once his contract has been finalised.