After rejecting a bid from the Red Devils for the 29-year-old over the summer, the Everton manager is now hoping to secure his star left-back's long-term future at Goodison Park
The left-back was a target for former boss David Moyes at Manchester United over the summer but, unlike team-mate Marouane Fellaini, he remains at Goodison Park after the club rejected all overtures.
With the window now closed until January, his boss is hoping to tie up the defender's future beyond the two years that currently remain on his contract.
"When the window is open I think it's the wrong time to speak about those things and so we hadn't discussed it," Martinez told reporters.
"But, now the window is closed, we are going to look into all the players in the squad and see where their contracts are up to. Then, individually, we will look to address that.
"It would just have created more instability if we had done that while the window was open."
Everton rejected a "derisory and insulting" double bid of £28 million for Baines and Fellaini in August, with the latter eventually moving to Old Trafford for £27.5 million on deadline day.