Teenage winger Deulofeu is currently on a season-long loan at Goodison Park from Barca, and recent reports have suggested he will remain on Merseyside next term.
However, Everton manager Martinez has insisted no decision on the Spaniard's future has been made, while admitting that keeping hold of him could prove tough should he continue his rapid rise.
"I'm not thinking about that (extending his stay) now," Martinez said. "What I am excited about is seeing Gerard's potential to develop and show his best in next five months.
"He is such a special footballer, one that anyone would enjoy watching, he's adjusted to life in the British game and understands what is needed - and he has done that quicker than we expected.
"We have an agreement (with Barcelona) over 10 months, it would be ridiculous to sit down now about the next step.
"We're all happy and will leave it until the end of the season and see where we are.
"If he does really well the chances of having him longer are slim."
The Spaniard was also quick to praise another of his young stars - Ross Barkley - following the England international's impressive display in Everton's 1-1 draw against Arsenal last Sunday.
"He (Barkley) takes everything in his stride," he added. "He's got all the attributes to be a great player.
"He never gets fazed by the situation; I don't think the scale of the game affects Ross.
"He's one of those players who is capable (of performing at the top level), but it is important to measure him on a weekly basis to make sure he doesn't burn himself out."
