After a promising start to the season which saw Martinez's men lose just one of their opening 17 league games, the Toffees have lost their way somewhat, having picked up just 11 points from the last 24 available.
And with hopes of a top-four finish looking more and more unlikely, Martinez is bracing himself for interest in the likes of Ross Barkley and Leighton Baines once again, but is adamant his players are not for sale.
"We want to keep every player who is part of our future and has performed well," Martinez said in The Sun.
"Financially we are in the strongest moment we have been for a long time.
"I would be worried if we had four or five players performing really well who were out of contract, but most are on long-term deals."
Fans have really taken to loan signing Romelu Lukaku since his arrival from Chelsea, with the imposing Belgian hitman linked with a permanent move to Goodison Park at the end of the season.
However, despite netting ten league goals already this campaign, Martinez insists that his loan acquisitions are temporary and is willing to let the likes of Lukaku leave if replacements can be found.
"When you are signing a loan player you know what you are bringing - a short-term relationship. That's it," Martinez added.
"There will always be good ones available, so I'm not worried."