Henson last appeared in the Ospreys' defeat to London Irish at the beginning of November and has completed just three full matches in almost eight months after an ankle injury brought his 2007/08 campaign to a premature end.
The star centre missed all four of his country's autumn internationals after aggravating an Achilles tendon injury but had been supposed to feature for the Ospreys last Saturday before pulling out to be with his partner, Charlotte Church, who is approaching labour.
Henson could yet miss another week of rugby if Miss Church doesn't give birth before the weekend, but Ospreys coach Sean Holley has at least stated that the 26-year-old is fully fit when he becomes available.
"Gavin was ready to play this week, but personal circumstances mean he's with his partner and we respect that," said Holley.
"So we'll monitor the situation next week and wish them all the best, but the good news is Gav's fit and ready to go."
While Henson's presence in Friday night's derby against the Dragons at Rodney Parade depends on his partner's situation, Jones, who has been suffering from a foot injury, has already been penciled in for the first of the Welsh derbies over the festive season.
"Ryan's ready to go," explained Holley.
"It's an unusual sort of injury he's had but the orthotics are working and he's pretty keen to get involved. We need to be aware that he's got a lot of rugby left to play, but we should see him against the Dragons.
"We could perhaps have pushed him last week, but perhaps made a bold decision not to. That's paid off. It just shows some of the courage now we've got in the group and the trust, but that means he's going to be right for a return."