Wests Tigers and Melbourne are poised to pull off the NRL's first loan deal with youngsters Paul Momirovski and Harry Grant to swap clubs in 2020 while being paid by their current employers.

Under the historic agreement, Tigers centre Momirovski will arrive at the Storm within the next week to offer another outside back option at the southern powerhouse, with an eye to returning to Concord at the end of the season.

Negotiations around a contract extension – Momirovski comes off contract in 2020 – are ongoing, with the Tigers still keen to have him on their books beyond this season.

In the meantime though they will continue to pay his wage this year, as the Storm will with rising hooker Grant, with both clubs loaning out a player in positions the other needs.

The unique nature of the arrangement is being closely scrutinised by the NRL but both clubs are hopeful of having Momirovski and Grant trading places within the next week.

Neither club has made an official announcement on the prospective moves.

Grant remains under contract at Melbourne for the next three seasons, and has been groomed as a potential No.9 successor for club champion Cameron Smith.

A 10-month shift to the Tigers will mean the 21-year-old bolsters Michael Maguire's flagging hooking stocks before returning to the Storm.

Grant played two first-grade games in the last two seasons but starred for feeder side Sunshine Coast Falcons in the Intrust Super Cup, claiming the club's best and fairest award and being named in the competition's team of the year.

Negotiations between the two clubs pre-date the Tigers' interest in Raiders star Joey Leilua, who finalised a three-year deal to move back to Sydney on Monday.

However the uncertainty around Josh Reynolds' playing future due to a domestic violence charge, and Jacob Liddle's recovery from an ACL rupture, have decimated the club's options at dummy-half.

Captain Moses Mbye has been training in the role over the pre-season having played at centre and fullback last year.

Momirovski's move to Melbourne in turn adds to Craig Bellamy's backline candidates, with premiership-winning centres Will Chambers (Japanese rugby) and Curtis Scott (Canberra) both moving on.

A year's rugby league education from Bellamy is seen as a significant attraction for the 23-year-old, who has a good relationship with Maguire having enjoyed a breakout 2019 campaign under the Tigers coach.

Momirovski finished the season representing the Prime Minister's XIII in Fiji after scoring eight tries and 21 goals in 11 games for the Tigers.

He would join the likes of new recruit Brenko Lee, Justin Olam, Marion Seve and Sandor Earl in contention for a starting role out wide.

While players have unofficially swapped clubs previously, such as Matt Moylan and James Maloney trading colours at Penrith and Cronulla three years ago, this is believed to be the first and most formal of what is effectively a loan arrangement between NRL outfits.

The English Super League has a dual-registration system, where top-tier clubs can loan a player to an outfit in a lower league, usually aiming to give young players more game time and experience.

As recently as December, Maguire advocated for a possible loan system "within the NRL" and between Super League and NRL clubs in the UK magazine League Weekly.

The Tigers coach became a fan of the English loan system during his time in charge of Super League powerhouse Wigan.

"I just see the value of kids, be it from here, being loaned to Super League clubs for a period of time," Maguire told League Weekly late last year. 

"It helps those teams. Even if you sent them there for two months… you might be able to find a way to send them there and help bolster up what’s going on over there at Super League level.

"You’d probably be able to do that every now and then with NRL teams... it [could] open up a different pathway and an opportunity for people to grow."