Pressley is disappointed that the 17-year-old turned down a contract at Brunton Park in favour of joining Leeds United, when first team football was a possibility with the Cumbrians.
The Scot, speaking at a press conference today, said it was hard to accept the loss of highly rated prospects Liam McCarron and Galloway to the Whites.
"It's something that disappoints me," he said.
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"I've said this before and I mean this; although I want to promote our young players from within the club, we have to keep our young players.
"We have to develop a situation where our supporters are seeing them for long periods of time.
"At this moment in time with both McCarron and young Josh, they're not seeing the development of the player and it's hard to accept."
Pressley is unhappy with what he believes is a flawed academy system that allows young talent to be picked off by bigger clubs.
Second year scholar Galloway was confirmed as a Leeds player earlier today for an undisclosed fee.
He was advised to stay put by the Carlisle manager.
"It's circumstances of the system, to a degree, because I spoke with young Josh on two occasions, I told him to speak to his parents on this and I expressed the fact that I didn't want him to leave the club," he said.
"I wanted him to develop here and play football here, I felt that was the best line for his development.
"He wasn't in agreement with that.
"The system has created a situation now where you have young players who I don't even think have to earn a contract and the club are under pressure to give them contracts.
"In my day you had to earn the right to a contract, now if we don't protect a young player who's had a couple of good games within a week, we're in danger of losing him.
"We offered a contract to Josh, which was declined, then you're in a position where if you don't negotiate what you consider to be a good offer, an offer that gives you an opportunity to earn money as he progresses in his career, you're in danger of losing him to a minimal amount of money through a tribunal. It's ridiculous at this moment in time.
"That's what the system is creating and it's incredible, it's not right."
Pressley spoke at length about the situation, saying it was 'wrong' for clubs like Carlisle to suffer the loss of young players in this way.
And he feels players like Galloway would benefit more from involvement with a lower league first team.
"In our conversation I said to him, he'll be going to Leeds United, I'm not questioning how they develop their young players, they're very good at it at that club, but he might be in a situation where he's in amongst the 18s squad. Here he's only two or three injuries away from being on our bench," said Pressley.
"For me the best form of development for a young player is to be in and around the first team, that's the quickest form of progression.
"He was around us, that's why I'm disappointed.
"I don't understand the reasoning for it but I also understand the club's take, we have to protect our own interests.
"We're forced into these things and that's what kind of angers me just now."