The Villa skipper made his first competitive start for the Three Lions in the 2-0 defeat to Belgium over the weekend, and despite the result stood out for his country.
Heskey, who made more than 100 appearances in claret and blue, says Grealish is in great position to become a starter under Gareth Southgate - having been impressed by the midfielder when he was at Villa Park.
"Definitely. When you look at what he actually brings to the table a word that springs to mind is ‘fearlessness’. In fact, he had that even when I was at Villa." Heskey said, speaking to Bookmakers.co.uk
"He was a 15-year-old at the time and at that age you can feel intimidated when you’re coming through, but he didn’t seem to feel that, he’s always gone out and performed his natural game – dribbling past people, taking players on, drawing fouls."
"He’s still very positive in what he does and doesn’t seem scared or daunted by anything because he’s very confident in his own ability and very comfortable with what he’s doing.
"Who glides past players like Jack Grealish does right now? There’s not many. There’s not many who run with the ball like Jack from midfield. We’re talking about a midfielder here, not a winger, but there’s not many players who are playing like he plays."
Grealish could be set to start once again for England in their final game of the Nations League against Iceland.
Southgate's side cannot finish top of their group following their defeat to Belgium, but could claim the runners-up slot should they beat Iceland and Denmark suffer defeat in Leuven, with a swing in goal difference also needed.
Elsewhere, fellow Villa teammates John McGinn and Conor Hourihane could both feature for their respective nations in their final Nations League games.
McGinn's Scotland will top their group with a win over Israel, whilst Hourihane and Ireland need at least a draw with Bulgaria to avoid finishing bottom of theirs.