Ireland and Leinster flanker Sean O'Brien is expected to join Championship side London Irish after this autumn's World Cup.
The 31-year-old is believed to have signed a lucrative deal with the Exiles, who are well-placed to return to the Premiership next season.
O'Brien, whose Irish Rugby Football Union (IRFU) contract expires after the World Cup, would put his international future in jeopardy if he moves to London Irish.
The IRFU only select overseas-based players in extreme circumstances, meaning O'Brien's Ireland swansong is set to come at the World Cup in Japan.
Johnny Sexton was selected by Ireland during his two-year stint with Racing 92 between 2013 and 2015, but is the only recent example of the IRFU picking players outside of Ireland.
O'Brien has 53 caps for Ireland and five for the British and Irish Lions, but has struggled with injury throughout his career.
He is now set to join former Ireland boss Declan Kidney and ex-Ireland defence coach Les Kiss at the Madejski Stadium.