The Croatia international has started only five Premier League games this season, leading to speculation that he could leave Goodison Park this month.
Jelavic is eager for first-team football with the World Cup only six months away and Martinez will allow the former Rangers man to move on for the right price.
When asked if Jelavic still has a role to play at the Merseyside club, Martinez said: "Absolutely, I felt he did really well when he came on against Stoke and he has been working really well for a while. I can understand his frustration when you do really, really well and there are other players performing well that can bring frustration to other key players in the squad. But Niki is still an important player in our squad.
"He's another one that has got a unique situation this season in that he's got a World Cup around the corner, but there has not been any changes in terms of Niki fighting for his place. If it's a situation where Niki can play football and he could prepare for his World Cup campaign, as a football club we get a deal that allows us to move on we will look into it. We will consider it. We've been very open with that."
John Heitinga is another Everton player who is eager to feature in the World Cup in Brazil, but the Netherlands defender rejected a move to West Ham on Thursday. The former Atletico Madrid man has also been linked with Roma and Martinez respects the 30-year-old's decision to turn down a transfer to Upton Park.
"Johnny is coming back [on Friday] and is going to train and is going to be part of the squad again," he said. "We need to understand that was a personal agreement. I always felt that Johnny has been a terrific servant to Everton and now he is in a key moment of his career with the World Cup around the corner. The next move is very specific for the needs of Johnny.
"We agreed terms with West Ham, but then obviously everything is down to the player feeling that is the right move for his career. I will support Johnny and as a football club we will support Johnny and help him to make the right decision in his career. In that respect we understand what happened and it is respect to see a player who wants to get the right feeling to accept the next chapter in his career."
Martinez went on to claim that both players have been model professionals in the midst of the transfer speculation.
"I think Niki and Johnny have been two extreme professionals this season and they have played a massive part in the achievements of the team on the pitch," he said. "It's only fair that we be open and we need to see with every situation that is on the table for the future of the players."