Crystal Palace Academy boss Gary Issott is delighted to see three of his players on tour with the senior squad.
Jake Gray, along with Hiram Boateng and Jerome Williams, were included by Tony Pulis on the tour.
"The big test now is if they can stay in that group," Issott told the Croydon Advertiser. "And then it's down to them to impress the manager more.
"It's great that Tony included them and took them away. The training has certainly been different out there, and it's a psychological one as well.
"If they get through that, and they've been getting up at 6am and having treble sessions, I think psychologically it makes you stronger. The manager is big on that.
"You never know if they'll come back to train with us. I remember the story of Wilfried Zaha, when George Burley wanted him and then he never came back.
"That's what you want really. Hopefully this will happen with one or two of them."
