Kevin Mirallas will miss the final three matches of Everton’s season with a torn groin muscle, the club have confirmed.
The Belgium international, 26, limped off towards the end of Sunday’s 2-0 Premier League victory over Manchester United.
Mirallas scored the second goal in that victory, which kept Everton one point behind fourth-placed Arsenal in the race for England’s final Champions League place.
The forward -- a 5.3 million pounds signing from Greek club Olympiakos in 2012 -- has scored eight times in 32 Premier League appearances for his club this season, with three goals in his last four games.
Everton visit Southampton on Saturday, then host Manchester City seven days later before finishing the season at Hull on May 11.
Martinez is expected to be without centre-back Sylvain Distin for the Southampton trip.
Distin, 36, was forced off at half-time on Saturday with a hamstring problem.
Martinez expressed his disappointment at the news but is confident Mirallas will be fully fit to take part in Belgium's World Cup campaign in Brazil.
The Toffees boss told Everton's official website: "Kevin's scans came back and they have revealed a small tear in his groin. He is going to be out for the season, which is a real disappointment and a shame because he was in a phenomenal moment of form.
"But the memory we have of his performance against Manchester United is a terrific image. The way he took his goal and how he was a dynamic force throughout the game, it was an outstanding performance.
"It's a great way to finish the season if it's the last game he is going to be involved in this campaign.
"It is not a major injury. It could be anything up to five or six weeks, and that's looking at the worst-case scenario.
"The most important aspect now is that we get him fully fit and ready to participate with Belgium in the World Cup."