Less than 24 hours after Hawkins was named to make his first-grade debut against the Gold Coast Titans at Cbus Super Stadium on Sunday, the NRL denied the Raiders' application for an exemption on the grounds other players were available in his position.

Former Raiders captain Alan Tongue has called on the NRL to increase the number of players in each club's top squad from 25 so promising youngsters are not denied the opportunity of being blooded into first grade.

The Raiders reached the limit of the $440,000 second-tier salary cap when hooker Kurt Baptise made his club debut in the 19-18 loss to the Wests Tigers on June 28.

Centre Jack Wighton suffered a broken thumb in the same game, prompting coach Ricky Stuart to call up Hawkins after the 21-year-old crossed for four tries for the Raiders' NSW Cup affiliate Mounties last weekend.

It is the second year in a row the Raiders have been prevented from handing an NRL debut to a promising youngster. Last season it was halfback Mitch Cornish, who was named to play in the round-26 match with the Cronulla Sharks before he was forced to watch from the sidelines when an exemption to the second-tier salary cap was not granted.

A former NRL coach, who didn't want to be named, said of the Hawkins' decision, ''all we're doing is stunting their progress''.

Raiders chief executive Don Furner was diplomatic with his response, admitting he would have been surprised if the NRL had agreed to their submission.

''It’s disappointing for Jeremy, but we’re confident he’ll get his chance to make his NRL debut with the Raiders in the future,'' Furner said. “With injuries to Jack Wighton and a season-ending injury to Edrick Lee earlier this year we were hopeful of an exemption, but we respect the NRL’s decision.''

Each NRL club operates under a $5.5 million salary cap for its top-25 squad, while another $440,000 is set aside for the second-tier salary cap. That was increased from $375,000 last season when the Panthers could not play Matt Moylan once players in the top-25 squad returned from injury.

The Raiders have this season used four players from their extended NRL squad: Baptiste, Matt Allwood, Shannon Boyd and Kyle O'Donnell.

They have also promoted outside back Brenko Lee from the club's under-20s team.

In making its decision, the NRL said there were players such as Reece Robinson who were available for selection and played the same position as Hawkins.

Tongue said the increased pace of the game and the amount of injuries teams were sustaining should lead to having a bigger pool of players available.

''I definitely think there's some room to move in that top 25,'' Tongue said. "It's a tough one because how far do you push it and how much leeway do you give to clubs.

''Having two guys injured in your outside backs [Wighton and Edrick Lee] is probably not enough to ask for compensation, there's a lot of clubs that have done it far worse. It's all about balancing the roster.''