Lions team doctor James Robson today delivered contrasting medical updates on Jamie Roberts and George North ahead of next Saturday's first Test match appointment with Australia in Brisbane.

Centre Roberts limped off during Saturday’s 47-17 victory against the New South Wales Waratahs, suffering a hamstring strain.

Wing North, though, is well on the way back following a hamstring problem. He resumed running today as the Lions completed preparations for their game against the Brumbies in Canberra tomorrow.

“Jamie is a grave doubt for this weekend, there is no doubt about that,” Robson said. “You only had to see how much discomfort he was in at the weekend. However, further assessment will be made later in the week as to his availability going forward.

“He has tweaked his hamstring. He has a strain. He got his leg extended, someone came down and flexed his back. It is unfortunate.”

North, who was yesterday rated as "less than 50-50" by Lions head coach Warren Gatland to be available this week, continues to make positive strides.

Robson added: “He (North) is an exceptional character and has worked really hard. He is back to running today. An accurate assessment on his availability for selection will take place on Wednesday. At the moment, I think he is doing very well and has a great chance of being fit for this week.

“We wouldn’t allow him to play if there was any significant risk. We will only return him to the coaches for selection if we are confident that medically he is fine.”