With Phil Jagielka struggling for a large chunk of the season with a hamstring injury, Stones has impressed alongside Sylvain Distin at the heart of the Everton defence - the Goodison Park outfit now looking set for a fifth-place finish and a UEFA Europa League qualifying berth.
Phil Jones is also now a doubt for England having injured his shoulder in Manchester United's 3-1 win over Hull City on Tuesday, and it has been suggested that Stones could earn a call-up to Hodgson's squad for the finals in Brazil next month.
"If he (Hodgson) decides the youngsters are going to be called up I can guarantee you they are ready," he said.
"John has had to face all sorts of strikers, he has showed incredible maturity. He's in a very good moment of form.
"Character-wise I can inform anyone that he is ready. If not (called up), John is a young man and needs to have a good summer to recover well for next season.
"The number of the age shouldn't affect the role of a player in the national team. We'll try to help the national team as much as we can."
"He is capable of anything," said Martinez. "It's about developing that potential. It's been a joy to have him at the club.
"He's now facing the possibility of playing in a World Cup so the sky's the limit.
"In terms of what's around the corner for any player on loan, you should ask their parent club."
