The 28-year-old was subject to interest from reigning champions Manchester United over the summer, now managed by former boss David Moyes, but Baines – unlike Marouane Fellaini – did not make the switch to Old Trafford.
Martinez has previously expressed a desire to tie down the former Wigan defender to a new contract, partly as reward for remaining at Goodison Park, but talks have been shelved for now.
|11/2||Leighton Baines is 11/2 with Paddy Power to score anytime against Fulham
“The only thing that concerns me is just to make sure he’s as fit as he can be and gets in a stronger position and balances the demands of England and club level.
“That’s what I’m focused on, that his day to day is perfect.
“Everything else, behind the scenes we’re happy with the situation and we’re making sure he’s happy as well.”
Baines struck twice in Everton's 3-2 victory over West Ham on Saturday, with both goals coming from stunning free kicks, and Martinez believes he is in the form of his career.
“In the last two games, once the window was closed, he could concentrate on his football,” the Spanish boss continued.
“I could be biased and see it from my own eyes, but when we played against Chelsea, it was the best two full-backs in England playing against each other, and then he came up with that sensational role on Saturday.
“He’s in a great moment of his career. In the last two games, Leighton has been sensational, probably because he’s been able to relax and enjoy his football.
“His contribution, to be able to score goals from deadball situations is a massive strength in any team, and he’s in a moment where the next three or four years are the best in his career.”