Wales Team Physiotherapist, Mark Davies, also has some positive news about wing Hal Luscombe, although hooker Robin McBryde is still a doubt.
"Hal's rehab on his hamstring strain is progressing well, he ran for the first time yesterday and he is responding well to the fitness programme we have devised for him," said Davies. "Most of his training is currently operating on an individual basis but he should be able to take a fuller part in squad training towards the end of this week.
"Robin sustained ligament damage to his knee and is currently undergoing treatment, his progress will be monitored daily, but there is an element of doubt over whether he will be fit enough to travel to Scotland."
Davies has had to rule out Thomas from the rest of the Championship but the prognosis is mixed concerning Parker and Charvis.
"Gareth (Thomas) had surgery on his thumb yesterday. He has fractured it in four places and the general prognosis is that he will be unavailable for six to eight weeks," he added.
"Colin (Charvis) is continuing the rehab programme on his injured foot and has been in camp for part of this week. He will not figure in the Scotland game and is now thought unlikely to be ready for the final game of the Championship against Ireland at the Millennium Stadium.
"Sonny (Parker) is making slow progress with his neck injury, although the progress is definitely there. He has a chance of being involved next week but at this stage it is a slim one."