Well, so much for this story. A rumor circulated on Wednesday in Australian media that San Francisco 49ers running back and punt returner Jarryd Hayne was considering a return to NRL this offseason. On Thursday, his manager, Wayne Beavis shot that down. Beavis said he spoke to Hayne earlier in the afternoon, and Hayne told Beavis he is "definitely staying", and there isn't a decision to make at this point.
I don't know enough about Australian media to say where the rumor developed, but my guess is an NRL executive slipped it out there for one reason or another. Whatever the reason, Hayne would appear to be sticking around for at least one more year.
When the season ends the first weekend in January, the 49ers will then likely sign him to a reserve/future contract. That contract is something teams use for players on the practice squad, or otherwise already free agents, to get them on a roster for the offseason. It is not a season-long contract, but rather gets them a shot in the offseason workout program and training camp. If they make the 53-man roster, they then get their season-long contract. Given that these go to practice squad players usually, the eventual contracts if they make the team will usually be for the league minimum.