Parrott has gone out on loan for two seasons running, first to Millwall, then to Ipswich Town in the latter half of last campaign, and this term he is at MK Dons in League One.
The striker failed to break the duck at Millwall in 14 appearances, netted twice for the Tractor Boys in 18 outings and has scored in only one match in the league since October for MK Dons.
Giles feels that the time is right for Parrott to get a grip on himself to become the best player he possibly can be.
The former Ireland man thinks the Irish prospect has not been taking optimal care of himself and hopes that whatever is hampering the youngster goes away.
Speaking on Off The Ball, Giles said: “I hope now he gets a grip of himself before it is too late to go on and becomes the player he should be.
“The only way he will do that is to work at it; behave on the pitch and work off the pitch.
“That is your starting point.
“You don’t have to have an awful lot of ability to try hard.
“He hasn’t been looking after himself, but hopefully he’s got it in his head that this doesn’t last very long.
“Careers go very, very quickly, I’ve seen it happen so many times with lads who start off very well, but get ahead of themselves, get a big head, are living it up, and then before you know it their career is finished.
“I think this young lad Parrott has a lot of ability, but he’s got to now get a real grip of himself to become the player that he should be.”
Though Parrott has gone through a dry spell in front of goal recently, he still has five goals and six assists in the league this season and he has been part of a MK Dons team that are challenging for automatic promotion out of League One.
Parrott scored Ireland’s winner in a 1-0 victory over Lithuania on Tuesday night.
