The Scotland international suffered concussion in the Toffees' FA Cup win over Swansea, but is expected to be fully fit to face title-chasing Chelsea at the weekend
Naismith was introduced as a substitute in Everton's 3-1 victory over Swansea City in the fifth round of the FA Cup on Sunday, scoring the second goal and winning the penalty from which Leighton Baines notched the third.
However, the 27-year-old failed to see out the match after a nasty collision with Jordi Amat in the closing stages.
|11/2||Everton are 11/2 with bet365 to beat Chelsea|
"Stevie (Naismith) has reacted really well. It was a little bit of a concern straight away when he had that delayed concussion," he told Everton's official website.
"Two hours after the game he was fine but for the next 24 hours it's then important you're in observation and we're checking all the signs are right.
"We've done that and Stevie is perfectly well. Over the next three or four days we're going to keep an eye on how he is recovering, but I would say that Stevie will be fully fit for the weekend because he's ready now to get back to work as normal."
In a further boost, Martinez expects striker Romelu Lukaku to return for the home encounter with West Ham on March 1 - with the Belgian ineligible to face parent club Chelsea this weekend.
He added: "It helps in a way that he's not available for this weekend because this game may have been a little bit too early for him to be involved with the team.
"But now we've got nearly two weeks to make sure that he's fully fit for the next home game and that's very much a realistic target."