The Mercury can reveal the duo has recently agreed to terms with the Dragons, with the club to announce the signings within the next fortnight.
The double coup also softened the blow left by the failed bid to lure Wes Naiqama back to the club next year, with the Knights speedster yesterday signing a three-year contract to play under Wayne Bennett in Newcastle.
Rein has been a revelation for the red and whites since his NRL debut in round one, making the most of the opportunity presented by the World Club Challenge injury to Cameron King.
The signing of Goodwin, who is expected to return from injury in four weeks, bolsters the club’s options to replace Newcastle-bound Darius Boyd at fullback.
Goodwin, who was in the process of renegotiating a contract extension before he suffered a knee injury in round nine, was given a guarantee the setback wouldn’t rob him of a contract for next season.
Also at the club, prop David Gower is off contract at season’s end and his manager Sam Ayoub has decided to wait until after the Origin period to negotiate a potential contract extension with the red and whites.
The Dragons have also tabled an offer to Adam Cuthbertson, but the back-rower is weighing up his options.
Michael Greenfield has activated an option in his contract to extend his time at St George Illawarra until the end of next season.