Ospreys have signed South African lock De Kock Steenkamp on a three-year deal from Super Rugby side Stormers.
The 27-year-old could potentially play for Wales after a three-year residency period, with the Welsh Rugby Union having approved his signing.
Each region can have up to eight overseas players, but two must be "time-serving" for international duty.
Ospreys hope Steenkamp's arrival will help mitigate the departures to Bristol of Ian Evans and Ryan Jones.
In a statement released by the Swansea-based region Steenkamp said: "Looking around the place and talking to people there really made me excited about signing.
"Hopefully I'll be able to link up with the squad soon and play a part in helping to make sure the Ospreys remain the best side in Wales as well as one of the best in Europe."
The Swansea-based region has announced the signing of another South African lock - Rynier Bernardo - in April after British and Irish Lion Ian Evans signed what turned out to be an aborted deal with Toulon.
Uncapped Southern Kings player Bernardo, 22, signed a three-year deal and is their other "time-serving" player.
The deal announced on 28 August, 2014 that ended almost two years of dispute between the WRU and regions included continuing with the previous regulations over foreign players.