Lee Byrne will spend time in an oxygen tent in a last-ditch attempt to shake off an ankle problem in time for Sunday's Heineken Cup quarter-final.
Byrne picked up the injury in the Six Nations against Ireland though is no longer wearing a protective boot.
He said: "I'll give anything a try to make that game so I'm having a few sessions in the tent. It's different but hopefully it will help."
Byrne hopes to rubber stamp his place as front-runner for the British Lions No15 jersey by helping the Ospreys to their first European semi-final.
Ian Gough also looks set to recover in time but Gavin Henson it out with his third injury this season.
Scott Johnson clocked on at the Ospreys on Monday but coach Sean Holley insists he is still in charge for Europe.
Former Wales boss Johnson arrived at the Liberty Stadium at the weekend to take up his post as director of coaching after a year in charge of USA Eagles.
But Holley will call all the shots ahead of the crunch cup tie in Limerick. He said: "Scott will take some time to soak up the environment and see what's going on before he steps in. I doubt he will have any input this week ahead of Munster."
He added: "Scott will be instrumental at the Ospreys. He will bring a new voice and fresh approach as well as his confidence."
Welsh players and management joined Deputy Minister for Sport Ken Skates at the Pierhead Building, Cardiff Bay earlier this week to reveal the Union's pioneering school-club hub initiative has been so successful the project will now almost double the scale of the original project.
The Scarlets, Newport Gwent Dragons, Cardiff Blues and the Ospreys look ahead to Judgement Day III which sees the Blues take on the Ospreys (2.30) and the Dragons tackle the Scarlets (4.45pm) at the Millennium Stadium tomorrow afternoon.
Ystradgynlais and Ynysddu played out a titanic struggle at Taffs Well in the SSE SWALEC Bowl semi-final. At the end of the game neither team could be separated after a 15-15 stalemate but Ystradgynlais go through on try count.
Blues strike first in JD III battle - Newport Gwent Dragons lock Andrew Coombs, WRU referee Dylan Llyr Jones and Cardiff Blues hooker Matthew Rees decide dressing room allocations for Judgement Day III
Wales Under 18 captain Calum Haggett has received a conditional offer to read Biomedical Science at St Anne's College, Oxford. WRU chairman Gareth Davies went to meet Calum and Coleg y Cymoedd Principal Judith Evans to wish him luck in his exams and pass on some of his personal experience.
Dodgy tattoos, carthorses, Avatar and soft chins are revealed by Wales Sevens players Tom Williams and Sam Cross as they profile the Wales Sevens squad taking part in Hong Kong this weekend in the latest round of the HSBC Sevens World Series.