Perpignan, freshly-promoted to the French Top 14, on Monday announced three signings including veteran Argentine scrumhalf Martin Landajo.
The 33-year-old Landajo has 84 Pumas caps and is part of the Harlequins squad that will play Exeter in the English Premiership final next Sunday.
Landajo was an unused sub as Quins came from 28 points down to beat Bristol in the semi-finals last Saturday.
He has signed a two-year contract with the Catalan club and will bring "a lot of experience at the top international level", said Perpignan general manager Christian Lanta.
Perpignan have also signed two players they faced on their way to winning Pro D2.
They are 25-year-old South African flyhalf Tristan Tedder, who was contracted to Toulouse but spent last season on loan to Beziers, and Portuguese hooker Mike Tadjer from Montauban.
Perpignan, the seven-time French champions, last played in the top division in 2018-19 when they finished last, winning two of their 26 matches to equal the worst-ever Top 14 season, although Agen have since taken sole possession of the record.