Ross Moriarty will leave Gloucester next summer, with Welsh region the Dragons his expected destination.
Gloucester confirmed in a short statement on Monday that the Wales flanker will quit Kingsholm at the end of the season.
Moriarty is understood to have lined up a deal with the Dragons, that will allow him to continue his Test career by returning to Wales.
The 23-year-old would have been left ineligible for Test selection under new Wales Rugby Union (WRU) policies had he remained in English club rugby.
"Forward Ross Moriarty will leave the club at the end of the season," read Gloucester's statement. "A product of the Gloucester Rugby academy, Ross has developed into an international player during his time at Kingsholm but has now agreed terms elsewhere.
"Gloucester Rugby will be making no further comment on the matter."
Moriarty has won 17 caps since his 2015 Test debut, having progressed through Gloucester's academy and opting to represent Wales rather than England, for whom he turned out at Under-20s level.
The St Helens-born back-rower toured New Zealand with the British and Irish Lions in the summer, but had his trip cut short by a back injury.