Roberto Martínez has described Tim Howard as crucial to the development of his Everton team but admitted it is “impossible to say” the USA international will be at Goodison Park next season.

Howard is set to be recalled for Everton’s Premier League trip to Manchester City on Wednesday having missed the last two games due to Martínez’s policy of selecting Joel Robles for the FA Cup and the Capital One Cup.

Robles featured in victories against City in the Capital One Cup semi-final and Dagenham and Redbridge in the FA Cup while Howard received ironic cheers from supporters when claiming routine crosses during league defeats by Leicester City and Stoke City, reacting on both occasions.

Martínez believes the 36-year-old’s strong performances, such as in the Boxing Day win at Newcastle United, are being overlooked and that the goalkeeper merits more appreciation. Howard’s experience behind an Everton defence disrupted by injury this season and his influence on young players remain vitally important, according to his manager.

“I don’t think he was being sarcastic,” said Martínez of the veteran’s recent exchanges with the Goodison crowd. “He cares about our football club and has an incredible attachment to it. He is trying to interact with the fans with the experience he has. Tim would never blame a defender for his mistake and I appreciate that. Tim has got 350 appearances in the Premier League which is a record for Everton. He is part of our club and our badge.

“He had mistakes but he had big moments. We need to be more understanding that sometimes you’re going to get that. His day-to-day work shows me the strength, power and positive effect he has on young players. I feel we are a stronger team with Tim Howard in the dressing room.”

The Everton manager, however, refused to be drawn on Howard’s long-term plans should his relationship with supporters come under further strain. Howard is under contract at Everton until 2018 having been awarded a four-year extension in Martínez’s first season at the club. But the manager admitted there is doubt over the keeper’s intentions beyond this summer.

“It is impossible to say that,” said Martínez when asked if Howard would be at Everton next season. “We need to take it game by game and week by week. I want Tim to feel stronger in every game. Watching him in training I don’t see a sign of weakness or him being worn down or tired. It is the opposite. He is up for the challenge, up for helping the team and keeping up standards. I’m sure every experience will affect what you want to do in the summer.

“We shouldn’t look that far away. We are here with a real focus of winning on Wednesday. That is all that matters. We have a incredible squad, a group of players here that I’m excited about and I’m looking forward to seeing them develop and Tim Howard is a big part of that. Whatever happens at the end of the season you cannot guess it now and it would be wrong to try to guess that.”