Fly-half Sam Davies is released with Rhodri Jones, Rory Thornton, Olly Cracknell. Nicky Smith and James King.
They will return to the Wales camp on Sunday to prepare for the Six Nations game with Ireland on 10 March.
The other Welsh regions play on Saturday and will not receive players from Rob Howley's squad, with Wales playing just six days later.
Ospreys will be boosted by six Wales squad members for their Pro12 match with Edinburgh on Friday, 3 March.