Greater salary cap concessions for long-serving clubmen may have kept Brett Morris at the Dragons according to St George Illawarra half Benji Marshall.

The Dragons' decision to grant a release to Test winger Brett Morris is more evidence the competition needs a salary cap exemption for long-serving clubmen, according to Red V halfback Benji Marshall.

The club, feeling salary cap pressure due to a number of back-ended deals following its 2010 premiership win, released Morris from the final year of his contract to join his brother Josh at the Bulldogs.

"I've heard all the negativity going around about letting 'B-Moz' go but people forget Brett wanted to play with his brother as well so it wasn't a one way decision," Marshall told NRL.com.

"From a club point of view we've still got a lot of confidence in the players we have here. Obviously Brett's the best winger in the world and he'd be a loss to any team but that's just the way the sport's become – it's not about loyalty anymore.

"Every club's a business and there's a salary cap that decides if you can keep players or not."

He said in Morris's case there should be an exemption in place for players that have been at one club for a long time whereby the club can pay players "what they deserve".

Rival clubs are going to keep being able to make larger offers to in-demand players to take them from clubs that want to keep them but can't fit them under the cap, Marshall noted.

"You can't be loyal to a club when you're getting $300,000 or whatever per year more from a different club," he said.

"Brett's got a family and you've only got a limited time in the game. People forget that. It's something for the NRL to look at, an exemption for one-club players to be paid and get that off the salary cap because it's a big deal and it affects a lot of clubs."

Salary cap pressure caused angst at Manly throughout 2014, with back-ended deals contributing to the departure of long-serving and popular clubman Glenn Stewart when the club couldn't table him an offer, while Anthony Watmough – another long-serving local junior – was granted a release at the end of the year.

"[Manly] has harnessed all those players and brought them through the grades. They should have the right [to pay them what they deserved] because they helped turn them into the players they are, to help them keep that player. It's something I'm pretty passionate about," Marshall said.

He said the Dragons could have afforded to keep Morris for an amount matching his market value if they'd had room under the cap.

"Off the back of the 2010 premiership, they had a lot of players back-ended which didn't help the situation, and other players got upgraded. That's just clubs, monitoring salary caps is not easy.

"Brett decided to leave and the club decided to release him. If we could've kept him I'm sure we would have."