Former Cameroon international striker Eto'o arrived at Goodison Park in the close-season, but made just eight Premier League starts and subsequently joined Serie A side Sampdoria on Tuesday.
However, Martinez - who refused to say if Monaco's Dimitar Berbatov is a transfer target - believes his squad has enough cover to cope with Eto'o's departure.
"At the moment because Arouna Kone's physical condition is fully fit, he's ready to give his best to the team so I don't think we need to replace Samuel in that position," said Martinez.
"We have players who have been performing in that number 10 position, Ross Barkley, Steven Naismith and with strikers we have Romelu Lukaku and Kone so I think we're strong there."
Everton are on an eight-match winless run in all competitions, but Martinez stated that the priority is to return his current squad to full confidence rather than adding new players.
"We're not looking in this window for solutions," he added. "It is fair to say that all the work we did in the summer was to have a strong enough squad to play all the competitions.
"The task is to get all the players back in their confident mood, we haven't lost the players we had last season. We have a strong squad heading in the second half of the season.
"Saying that as a club we always try to use windows in our favour and we'll never stop trying to help the players in our club."
One particular boost for Martinez is the news that James McCarthy could be involved in Saturday's trip to Crystal Palace after a month-long absence with a hamstring injury.
And Martinez is relishing the return of the Republic of Ireland international.
"James McCarthy is a very important player, we're going to get a James McCarthy who is fully fit and refreshed for the second half of the season, it's about introducing him at the right time," he said.
"McCarthy was an important part of our season last year, he's infectious in the way he plays."
