The England international returned to action last month after missing the start of the campaign because of a knee injury.
And although Barkley has only scored one goal since March, Martinez believes his sharpness is increasing.
Martinez has been particularly impressed with the 21-year-old???s displays against Wolfsburg, Tottenham and Hull City in recent weeks.
???Ross Barkley is a goal scorer, when I say ???goal scorer???, he has the instinct to score goals as he???s got the talent in the final third to be really dangerous,??? Martinez said.
???I don???t look at stats in that way. I???m looking at stats now he???s fully fit he???s been consistently strong now for a while.
???It was a real setback when we started this season and he picked up an injury, but the last two games he???s played a big role in both games – at Wolfsburg and Spurs – and Hull. So slowly he???s having his best level.???
The 1-1 draw against Hull at Goodison Park means Everton have just one victory in five Premier League games.
But Martinez believes the statistics are slightly misleading, as he prepares his side for the visit to Manchester City on Saturday.
Martinez said: ???Stats are a little bit confusing. In the same way I could say, ???we???ve only lost one in the last 10???.
???So I wouldn???t be too relaxed, I???m just saying we???ve only lost one in 10, in the same way I wouldn???t be too concerned of looking at the way you are looking at it.???