English Premiership side Worcester signed second row Anton Bresler on Thursday and announced Christian Scotland-Williamson is leaving to chase his NFL dream.
Scotland-Williamson will go to Florida to work with NFL coaches over the next few months in the hope of earning a place on one of the 32 teams for the 2018 season.
The 24-year-old made 23 appearances for Worcester after joining them in 2014, with his time at the club disrupted by injuries.
Scotland-Williamson said: "This is a once-in-a-lifetime opportunity for me and one that I simply can't turn down.
"I'm incredibly excited about testing myself and trying to get on the team roster at an NFL club."
Filling the gap left by his exit is Namibian-born Bresler, who arrives from Edinburgh.
Bresler, 29, who made 61 appearances for Edinburgh after joining them in 2014 from Super Rugby outfit The Sharks, said: "I'm genuinely excited at the prospect of playing Aviva Premiership rugby and can't wait to get out on the field to show what I can do."