Cardiff Blues can confirm Sam Warburton has suffered a low-grade medial ligament strain and will be side-lined for approximately six weeks.
The flanker suffered the knee injury in the first half of Friday’s 24-24 Guinness PRO12 draw with Ulster in Belfast.
Following scans in Cardiff yesterday, Warburton will now begin a rehabilitation period and could be back in contention if the Blues reach the final of the European Champions Cup qualification play-offs.
Cardiff Blues head coach Danny Wilson said: “Sam has a low-grade medial ligament strain, which will put his out for approximately six weeks.
“It is good news considering how it could have been. He’s very experienced and a good professional who knows his body. He knows if he works hard to get it right he will be back relatively quickly.
“If we are fortunate enough to make the second play-off game we envisage him being fit.”
George Earle suffered a similar injury to Warburton at the Kingspan Stadium with a slightly shorter recovery time.
It has also been confirmed that Blaine Scully sustained a dislocated elbow, which will require further investigation before a detailed prognosis can be made.