Wales star Hook has enjoyed an impressive tour to date
James Hook has given Lions head coach Ian McGeechan a fitness boost ahead of the first Test in South Africa.
The Wales fly-half will miss Saturday's first Test after suffering a head injury in their bruising win over Southern Kings on Tuesday.
It had been feared Hook could miss the rest of the tour, but McGeechan insists he should be fit to face the Emerging Springboks on Tuesday.
"James Hook trained today (Thursday)," revealed McGeechan.
The Ospreys fly-half was set to visit a neurosurgeon next week to determine if he has concussion.
If he had, Hook would face a mandatory three-week break from rugby, which will rule him out of the rest of the Lions tour.
But McGeechan hopes the 23-year-old will be available for selection for Tuesday's game with the Emerging Springboks at Newlands in Cape Town.
"He is being continuingly monitored by the medical staff," said McGeechan.
"But he is doing well and we hope he will be available for Tuesday."
But McGeechan conceded that Scotland prop Euan Murray is set to miss the rest of the tour with an ankle injury.
Both Hook and Murray suffered their injuries in Tuesday's 20-8 victory over Southern Kings in Port Elizabeth.
Hook was the more likely contender for the Test 22 because he had been widely expected to provide midfield cover following an impressive tour, which has so far yielded 32 points for the Wales star.