British and Irish Lions winger George North has been passed fit for Saturday's first Test against Australia after recovering from his hamstring problem.

North was a doubt for the series opener at Suncorp Stadium after sustaining the injury a week ago, but assistant coach Rob Howley revealed he has fully recovered.

"George came through a fitness test this morning and I've never seen him in better shape. He'll be available and that's a big boost for us," Howley said.

North's ability to beat defenders making him a key weapon against the Wallabies and the 21-year-old is set to be named on the left wing at tomorrow's team announcement.

"We've looked after him over the last week to 10 days and it's a huge boost to have someone like him available," Howley said.

"Over the last 12 months I haven't seen him in better physical shape and that's why we took the decision to get him 100 per cent physically well.

"I'm sure he's looking forward to playing at the weekend - if selected."

Centre Jamie Roberts and wing Tommy Bowe are almost certain to miss the first Test with respective hamstring and hand problems, but Manu Tuilagi could yet feature following a positive update on his shoulder injury.

"Jamie is progressing. He ran today and is unlikely to be fit for the weekend, as is Tommy Bowe," Howley said.

"Tommy is more likely to be available for the second Test. Manu is improving every day and the strength is coming back into his shoulder and he will be touch and go."

North's availability has served as a timely lift to the Lions after they slumped to their first defeat of the tour in a 14-12 loss to the Brumbies in Canberra.

It was comfortably their worst performance Down Under and Howley insists the Lions' resilience will be determined by how they react to the setback.

"We had a meeting about the game and the nature of a Lions tour is that you must move on. We're bitterly disappointed and will take the hit," he said.

"On a Lions tour you talk about the importance of momentum and in the last four or five matches we've had momentum. Now it's about how we react to that game.

"It's important that this team and squad come together and I'm sure that everyone will be behind the 23 selected for Saturday.

"Absolutely something like this can make you stronger. It gave us a reality check, in particular at the breakdown. We move on and that's the nature of a Lions tour."

Live radio coverage of Australia v Lions from 10.55 on Saturday 22 June on RTÉ 2fm and RTÉ.ie (RoI only).