Robin van Persie vows to prove his worth at Manchester United

Manchester United striker Robin van Persie is determined to prove himself again next season and will not be happy sat on the bench.

Van Persie, 31, scored 10 Premier League goals last season in an injury-hit campaign but looked way short of the form which fired United to the title in 2012-13.

That has led to speculation that the Netherlands international could become surplus to requirements at United, but he insists he still has what it takes to perform at the top level.

"Am I worried? No, I'm totally relaxed," Van Persie told reporters when asked about his future. "I have a contract with this club until 2016.

"Things could change now, but that all depends on Manchester United not me. Believe me, I'm relaxed -- I'm not going to be part of a puppet show.

"In August I'm 32. But I still have the ambition to play for another eight years.

"In a few years' time I may have to accept that I will no longer play at the very highest level. I don't think that moment is coming now. I still feel very, very fit.

"Playing in the first-team is very important for me. This is why I will probably step down one level when I am 36 or 37. But not now.

"Whenever I have been fit at United I was playing in the first team all the time. People talk about my injuries, but I've only had one this season.

"I've seen too many players quit early. Most of them regret this soon after. I've seen those players in the national team and at my own clubs. Even big legends have regretted their retirement. Look at Paul Scholes.

"He did quit the game but he kept training and was missing football so much, because he knew he was still capable of playing at that level."