That's the view of Gosport Borough boss Shaun Gale having worked closely with the Blues' academy prospect this season.
Kavanagh achieved a lifelong dream earlier this month when he was handed his Pompey bow in the EFL Trophy defeat to West Ham under-21s at Fratton Park.
It came on the back of a 'fantastic' start to season after securing a loan move to Gosport.
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Borough boss Gale was blown away by the 18-year-old's performances for his team prior to the Southern League Premier South season being suspended because of the second national lockdown.
Kavanagh's attitude and willingness to learn have stood out for the Gosport manager as well as his outstanding ability.
Gale believes his Blues bow came as reward for his fine form at Borough and feels he is one to watch for the future.
He said: ‘Harry has been been fantastic, he’s going to be a good player.
‘He takes things on board.
‘He’s going to be a very, very good player, Harry. He’s got a great attitude and is a very good lad.
‘I think he’s one for the future for Pompey, he really is.
‘He needs to play games and Kenny knows that as well.
‘Kenny has got a wealth of experience and he knows he needs to be out playing men’s football and that’s what he’s doing.
‘If we can be a part of that process to help him into the Pompey first team then that is great for us as well.’
Gale has worked with the teenager on the 'weaker' defensive side of his game at Gosport.
But the Borough boss insists Kavanagh has more than enough time to improve in that area.
And Gale reckons he's giving himself the best opportunity to eventually break into the Blues’ first team by getting regular game time in senior football while still in the early stages of his career.
He added: 'Harry knew that the defensive side of his game was the weaker part of his game and we’ve worked with him on it and will continue to do so as Pompey, I’m sure, are doing the same.
‘If he improves that side of his game, going forward he’s got real good quality, he’s still only young and learning.
‘That’s the whole idea of it to come out and get experience playing against men.
‘Getting those games under his belt, he’ll be a better player for Pompey for that.’