The Spaniard insists it would not be in the 20-year-old's best interests to leave Goodison Park, despite reported interest from the likes of Chelsea.
Barkley is expected to play a key role for England at the World Cup but even if the 20-year-old stars in Brazil, he will not be leaving Goodison Park if Martinez has his way.
MORE: Top 25 infamous moments in World Cup history
While the obvious reason for Martinez to keep Barkley would be self interest, the Spanish manager claims he is more focused on what is best for his young charge.
"[A transfer] would be wrong for him," Martinez said. "I always feel as a manager, you develop a relationship with players and you're always honest with them.
"Ross is a phenomenal talent, probably the best English talent I have ever seen, but he is not the finished article yet and you need to be very careful. It's our duty to protect him and I know Everton is the perfect place for him for the next 12 months."
Martinez also hinted that if Everton breaks into the top four of the Premier League next season and qualifies for the Champions League - the club finished fifth in 2013/14 - it might be able to convince the attacking midfielder to stay on Merseyside.
"In football, obviously you can never speak about the future. Obviously we need to come along and try to get into the top four positions to offer players like Ross the next stage of their development," the former Swansea and Wigan manager said.
"But Ross is delighted at Everton and feels very much in the right place at the right time of his career."
Barkley played 38 games in all competitions for Everton this season, scoring seven goals.