The 20-year-old scored a stunning opener in the 3-2 defeat at home to Manchester City which ended the Toffees' chances of qualifying for the Champions League.
That breathtaking strike only enhanced his chances of making the squad for Brazil but Martinez appeared to be the only one inside Goodison Park who did not marvel at the first-time effort from 25 yards.
"The concerning aspect is that I didn't even get surprised by it as you get used to that type of quality," said the Spaniard.
"I thought the goal was a magnificent piece of skill from Ross.
"He is a phenomenal talent and the best England talent I have seen and the character that goes along with that quality is special.
"He finished (the season at Goodison) with another incredibly special strike and we need to give him good care because he is special.
"I respect (England manager) Roy Hodgson's vision and his ideas for the World Cup and whatever he decides will be the right thing.
"If Ross is called up he will be ready, he offers something unique and there is no one in the England camp like Ross.
"At the same time he is a young man and we need to look after him. The character of Ross is ready to embrace anything that comes his way but if he is not at the World Cup we will use the summer to regenerate him and refresh him for the next campaign."
Everton are all-but guaranteed a fifth-place finish as Tottenham are three points behind heading into the final game with a goal difference which is 19 worse than their rivals.
Missing out on the top four is a blow, as for much of the season Everton put up a sustained challenge which only faltered in the final few games.
Despite that Martinez, who when he took over from David Moyes in the summer was not predicted to do as well as he has, thinks the campaign can be judged a success.
"It is disappointing because Champions League (qualification) was the dream we had at the beginning of the season," he added.
"If we get fifth that will be a phenomenal step forward and we have to make sure we can embrace those demands and take our name where it belongs in European competition."
Barkley's opener was celebrated wildly by Goodison Park, which dispelled the pre-match suggestion that Evertonians would be happy for their side in order to significantly damage the title hopes of local rivals Liverpool.
City hit back with goals from Sergio Aguero and two from Edin Dzeko before Romelu Lukaku's header set up a tense finale for the visitors.
"In the last 20 minutes we gave it a proper go, showed great character, but we showed an incredible bravery from the first second to the last," said Martinez.
"I thought we didn't deserve to lose the game and everyone who watched it understood if anyone was questioning our integrity as a club they had no reason to do it.
"The effort of the players was clear to see and the way we celebrated Ross Barkley's goal was as big a roar as there has been at Goodison this season.
"I think it is clear we tried absolutely everything to beat Manchester City."
- Sports & Recreation
- Manchester City
- Goodison Park