The pair will boost Ospreys at the Brewery Field when eight other Wales internationals will watch on ahead of the Six Nations.
The home side are without centre Owen Watkin, fly-half Dan Edwards, Hardy, hooker Dewi Lake, lock Rhys Davies and flanker Harri Deaves while Dragons are denied the services of number eight Aaron Wainwright and lock Ben Carter.
The Rodney Parade team have won their last four games in Newport but, after an agonising 22-20 loss to Munster in Cork last weekend, are still chasing an elusive away success in the URC.
They have not won away in the competitions since beating Scarlets in April 2022, while their last league victory outside Wales was at Connacht in October 2021.
Dragons have won just twice on their travels to Ospreys in the league – a 31-20 success in Bridgend in March, 2021 and a 21-16 win in Swansea in October, 2010.
