Sam Warburton feared he would not recover from an ankle injury in time to lead Wales at the Six Nations.
The flanker sustained the problem playing for Cardiff Blues against Ospreys in November, rolling his right ankle in a collision with international team-mate Justin Tipuric.
Warburton only made his comeback in a 74-6 hammering of Calvisano in the Challenge Cup on Friday, a welcome return for the national team captain, with Wales' Six Nations opener against Ireland in Dublin scheduled for February 7.
"I did fear initially that I wouldn't get back for the start of the championship," he told Wales Online.
"I wasn't sure if I had completely ruptured my ligaments, which would have required an operation and I don't think I was too far away from that.
"I did completely rupture one of the ligaments in my right ankle, but because it was only one of them they said I could get back on an eight-week schedule.
"So I just missed that worse-case scenario, which would have been pretty bad news. Luckily I just escaped the operation.
"It was a real relief. I knew I had done something, I tried to play on for 10 minutes but I couldn't put weight on my foot.
"I know [Blues coach] Danny Wilson has spoken to Gats [Wales coach Warren Gatland] and I think they are both happy for me to play, as long as I want to, which I definitely do."
Warburton remains Gatland's first choice to skipper the side, but the 27-year-old knows he must prove his readiness if he is to start against Ireland.
"Even though it's been announced I am Wales captain, first and foremost I've got to get some fitness and form back," he said.
"I have got to play games definitely, so I want to get some more game time here at the Blues.
"A couple of breakdown decisions didn't go my way against Calvisano and that's just a little bit of rustiness when you are diving in over the ball.
"The speed of a game is difficult to replicate in training without the risk of injury. Hopefully I'll get another game under my belt and get those cobwebs off and get the lungs going again."