England, ninth in the FIFA rankings, breezed through their Euro 2016 qualifying group with a 100 percent record against modest opposition but can expect a sterner test from sixth-ranked Spain on Friday and France next Tuesday.
"I think it will be a real test of how England use their squad in a different way, because you are playing against probably the best team in the world (Spain) in terms of possession," Martinez was quoted as saying by the British media.
"It is probably the type of challenge they need going into the Euros, because it is completely different to what they encountered in the qualifying group.
"What I always look at with Ross is what he can do offensively against these types of teams because these teams, when they lose the ball, have left space.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
"You need pace and power to break into that space, and Ross gives you that," the Spaniard added.
Barkley has scored six goals in all competitions this season but only one of those strikes has been for his country and Martinez says it is up to England's management to get the best out of the midfielder.
"Ross is the best in the business. If England don't want to play like that and just wait and get set and have the ball, then Ross is not special.
"It depends what England want from Ross really," he said.
"England, depending on how they want to use him, are going to (determine whether he will) be influential or not."
(Reporting by Simon Jennings in Bengaluru; Editing by John O'Brien)
