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.
Should that be the case, Martinez insists the 19-year-old would cope with the pressure.
"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."
Martinez also took time to hail Romelu Lukaku, the on-loan Chelsea forward who has netted 14 Premier League goals in another impressive campaign.
"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."
