The 22-year-old Gelling has made only 12 Super League appearances since joining the Warriors from Auckland Vulcans 18 months ago and, out of contract at the end of the season, he is running out of both time and opportunities to prove his worth.
Unable to play for either of Wigan's partnership clubs, Leigh and South Wales Scorpions, due to visa restrictions, Gelling has also been denied the chance to gain match practice with the club's Under-19s because of the rigid age restrictions.
The anomalies of the controversial dual-registration system are further highlighted by the decision of Warrington's veteran stand-off Lee Briers to make his comeback from injury by playing for Swinton against Whitehaven on Thursday night.
Coach Shaun Wane, who needs to plug the gap when Richards returns to Wests Tigers at the end of the season, believes Gelling has considerable promise but admits he needs to see more of him before he can offer him a new deal.
"He's a good player," Wane said. "He's got talent. He's a big athlete and he's got some good skills.
"He's also a good person. I am hoping to keep him on board but what gets to me is him not being able to play. That is causing problems.
"I just don't get it. I don't see how it can carry on. I need to see Hame Lauaki and Gelling play.
"They need to play regularly but it's not happening yet. There is a chance this weekend for Gelling and I might play him against London in our next league game."