Wales front-rowers Gethin Jenkins and Richard Hibbard are injury doubts ahead of Saturday's final Six Nations match against Italy in Rome.
Wales sit in third place on the championship table and must win big to hope to snatch the title away from England and Ireland .
A hamstring injury forced prop Jenkins off at half-time of Saturday's 23-16 win over Ireland while replacement hooker Hibbard is following concussion protocols.
Saracens prop Rhys Gill is training with the squad as cover for Jenkins.
The news comes as blow to Wales, who are already without tighthead prop Samson Lee beacuse of an Achilles injury.
Uncapped Exeter prop Tomas Francis, who was invited to train with Wales last week, has now officially joined their Six Nations squad and could well feature off the bench this weekend,
Wales head coach Gatland will name his team on Tuesday.
Wales assistant coach Robin McBryde said there was no chance they would call on veteran prop Adam Jones, who announced his retirement from international rugby earlier this season after earning 95 Test caps.
"It was Adam's decision in the first place to hang up his boots on the international front," said McBryde.
"There is no need to call him at the moment. We have enough strength in depth.
"The spirit is good, and by keeping us in the hunt for the title, everyone has come in with that appetite and an edge to build on the momentum for the last few days," he said.
"It helps that we [play] first. We don't know what the situation will be at the end of play. We have to win the game first," added McBryde.
"Italy have strengths of their own, and you have to base any victory on defence and making sure that's in place before you turn your efforts into scoring.
"Their victory against Scotland proves their calibre. We know it's not going to be easy, so we are going there just to try and get a result.
"What happens the rest of the day, we are not in control of. We are not thinking about the points difference. We are just going there for the win.
"It's the last competitive game with something riding on it before the World Cup, and we have to treat it as such.
"It's all about Saturday and building on the momentum we've already created, and just making sure we finish on a high."