Former boss David Moyes saw a £15 million bid rejected in the summer for the left-back, who has 18 months left to run on his current deal.
|11/2||Leighton Baines is 11/2 to score anytime against Aston Villa|
"There's no train of thought on that at the moment," the former Wigan boss explained.
"All that matters is that Leighton is enjoying his football. That's the only thing I'm focusing on."
Despite the uncertainty surrounding his future, Martinez insists he is delighted with the 28-year-old’s form this season and believes he is performing better than ever.
"He's increasing all his personal stats," he continued. "I think all his performance stats have improved from last season.
"That, for me, is very important - someone of his age and maturity is starting to enjoy his football in a great manner. The fact that he's developed his performance level as he has in the early weeks of the season is very significant. That's what matters to me.
"Everything else is just a case of trying to find an issue from the outside and see what we will comment on."