Although Martinez admits losing the centre-back is a major blow, he is confident the Three Lions have sufficient strength in depth to do well without him.
He said: "Without a doubt, it is a big, big blow. More than just the type of player Rio is, it is his character, his leadership and his understanding of the game.
"When you are trying to guess about who is going to do well in the World Cup as a team, those moments are huge.
"But on the other side, you are looking at the possible players who could step up and play instead of Rio.
"You have got huge options, with players that have had great seasons in the Premier League, which we have to remember is the best league in world football.
"So I would say it is a disappointment, but I think the replacements are good enough and ready enough to take England as far as they would have gone with Rio."