He said: “No one knows how long they have left and the eye trouble really brought that home to me.
“So I look to enjoy each day and game for as long as I can play. I hope I have many years to come at this level.
“I’ve two years left on my contract and as long as I’m enjoying my football I want to continue. The young players at the club like Cristiano Ronaldo and Wayne Rooney keep you young.
“I’ve really enjoyed playing with them this season and we’ve some great young players who are going to be at the club for years to come, which is great for the future.”
