Eight players will head back to their Welsh regions with Josh Turnbull and Liam Williams returning to the Scarlets and Alun Wyn Jones and James King released back to the Ospreys.
The quartet of Scott Andrews, Lou Reed, Josh Navidi and Andries Pretorius return to the Blues.
As per IRB regulations, Paul James (Bath), Craig Mitchell (Exeter Chiefs) and Olly Kohn (Harlequins) have been released back to their clubs as have Gethin Jenkins (Toulon), Mike Phillips (Bayonne), Lee Byrne (Clermont Auvergne) and James Hook (Perpignan).
The players will return back to the Wales RBS 6 Nations squad on Monday, 18 February.
