The 21-year-old has failed to regain the sparkling form of last season, a tour de force playing behind the striker.
He has regularly found himself shunted out to the left of midfield in the current campaign and while that may have contributed to his dip in performance, Martinez has full faith in the player's ability to bounce back.
"As young player you keep developing and growing and the thing I admire about Ross is that he will never shy away from the ball," said the Spaniard.
"He had a couple of situations against West Ham (in Tuesday's 1-1 FA Cup draw) where he gave the ball away and he quickly wanted to get it back and that is what pleases me.
"I think Ross Barkley is a phenomenal talent but he is still a young man and is still learning and he needs to get through certain periods where he can make decisions in a better way.
"But he is a reliable character and is someone who will be positive in the squad whether he is having a good or a bad game.
"When you have that personality and character you will get into a point when your talent will shine.
"Ross Barkley is the least of my worries."
Barkley was such a threat last season that teams are now paying him special attention.
While that may have restricted his ability to influence games as much as he did, Martinez believes his team have to take advantage of this in other ways.
"Last year he was a young player enjoying his football; this season he is Ross Barkley and that brings a completely different approach from the opposition," he added.
"That means it is harder to find space, it is harder to get into positions where you can affect the game and that is something when you overcome it, it becomes an advantage.
"He is still getting through that process so I don't see it as being clear-cut in terms of how effective he was last season and not that effective this season.
"He is evolving, he is becoming stronger and better and his tactical awareness is improving all the time.
"What we have to remember is when Ross Barkley is on the pitch the opposition use two players against him and somone else should be free elsewhere and we need to use that.
"We are a flexible team in that respect and it has always been a strength of ours and we will carry on doing it."
Barkley was a mixture of brilliant and disappointing against West Ham in midweek, which saw Romelu Lukaku snatch an added-time equaliser to earn a replay.
The Belgium striker said afterwards the players had asked Martinez to be slightly more direct but the manager dismissed suggestions a dressing room delegation persuaded him to alter his style.
"I am always talking with the players and we try to prepare from game to game," said the Everton boss.
"We always share a lot of information but it has come out in a way that (suggested) it was a one-off meeting and we had never spoken before.
"It was a normal approach
We need to use players in specific ways from game to game so you can get a better performance and I thought against West Ham Rom had a very effective game."
With just one win in 10 matches there have been suggestions of unrest behind the scenes but Martinez rejected that.
"I am sure from the outside you are always going to try to find answers - if anything that has made us even stronger and made us a little bit more focused on what we are and what we want to achieve.
"The clear assessment you can make of the squad is it is stronger than ever, focused and we have a real competitive edge about us and we are desperate to be involved in games to kick-start our season.
"The winning mentality that I always felt was in the group was strong and now it is just getting back to a simple approach, which is just the next game and making sure we can perform in a manner which can start a real good run of performances."
Source : PA
Source: PA