Josh Earl, Callum Roberts and Melle Meulensteen will join the first-team squad in July after completing their scholarships.
With no development squad at PNE, it is a big jump from the youth set-up to the senior squad.
But the challenge is there for them to catch the eye when they are training with the squad are on a full-time basis.
Grayson told the Post: “We can only give a few contracts out and the three lads have deserved them.
“They have got to work hard to improve and they are not here to make the numbers up.
“The lads have to be ready to perform near the first team or go out on loan to get game time.
“They are different types of players. Josh can play anywhere down the left side, Melle is technically a very good footballer and Callum has shown his quality in goal.
“All three have trained quite regularly with us this season so we know plenty about them.”
Earl is just back from a work experience loan spell with Lancaster.
He helped them win the NPL First Division North title and was in the Dolly Blues side which won 5-1 at Glossop North End to clinch top spot last Saturday.
Grayson says loan spells are a good way for youngsters to gain experience, perhaps more so than playing in an Under-23s side.
“If you aren’t going to be near the first team, it is good to get young players out on loan to get the experience of playing mens’ football,” said Grayson. “Josh has had that recently at Lancaster and that will have done him good.
“I watch a lot of Under-23s football and it doesn’t quite have the cutting edge which is required to get you ready for first-team football.”