The Rodney Parade outfit are currently second in Pool Two and will be determined to pick up as many points as possible from their back-to-back clashes with Bordeaux Begles.
Coombs was part of Wales’ autumn squad and was selected to face Tonga but failed to play due to a back injury.
He was bitterly disappointed by the set-back but is determined to make up for lost time in a Dragons shirt.
“I had a trapped nerve in the middle of my back, so every time I moved it would catch and there was no way I could play,” said Coombs.
“It’s part of the game, getting injuries, but you knew if you had played well you had a chance to play in the Australia game.
“It was tough to watch the first two games and I thought I may get a chance against Tonga.
“It was disappointing to miss out – the toughest day I’ve had in professional rugby – but there was no way I could have played.
“It was a tough campaign for me, training for five weeks and getting no reward.
“Cory has been playing fantastically well by all accounts so I’ve got to play well to keep my place – I’m just keen to get out there and get on the field.
“The pressure is on, but I’ve just got to go out there and do what I can and play my normal game.
“I think it’s fantastic the strength in depth we have, it is brilliant for when we have players away with the Wales camp.
“Rob Sidoli has been playing out of his skin and it’s great to have his amount of experience in the squad – the young players can learn so much from them.”
Fellow internationals Hallam Amos and Toby Faletau also return amid nine changes to the Dragons team.
