Alun Wyn Jones and Richard Hibbard have been called up to the Welsh squad for Saturday's RBS Six Nations clash with England at Twickenham.
With Bradley Davies suspended for the rest of the tournament following his tip-tackle on Ireland's Donnacha Ryan two weeks ago, Jones has been drafted into Warren Gatland's squad as a replacement after proving his fitness in the Ospreys RaboDirect PRO12 win over Aironi on Friday night.
Hibbard, meanwhile, has been brought in as cover for Huw Bennett and Matthew Rees who are struggling to overcome calf strains ahead of the trip to London.
The Ospreys forwards will join up with the training squad on Monday with Gatland set to name his starting XV later this week.
"(We're) a little concerned with the two hookers. (We're) not sure whether they are going to be quite right, which is disappointing," said Gatland.
Wales have a number of injury concerns ahead of the England tie with George North (ankle), Ryan Jones (dead leg), Rhys Priestland (calf) and Justin Tipuric (ankle) all forced to sit out training during the week.
A number of players were released back to their clubs for games over the weekend and Gatland is hoping the decision does not prove too costly.
"I'm hoping not too many players pick up injuries with their regions," added Gatland. "If that's good we should have a reasonably full complement of the squad to train next week, which will be good for competition.
"With the two second rows coming back and hopefully the two hookers won't be too far away as well."