The Merseyside outfit strengthened in the summer with the likes of James McCarthy joining from Wigan Athletic for a reported £13m, as well as the captures of Gareth Barry and Romelu Lukaku on loan deals.
"We're in the position where we've got a bit of money to try to improve the squad for the next window and we're going to do that from window to window," the Liverpool Daily Post quotes Martinez as saying.
"We have to because I'm sure next time the question will be 'who we are going to lose now', so improving the squad goes without saying. We have got a little bit of money and will always carry on trying to identify targets that can help the group."
The Toffees failed to progress into the fourth round of the Capital One Cup due to a 2-1 defeat to Fulham on Tuesday evening.