The Australian-born second-rower was stretchered off in the first half of Wales' scratchy 11-10 win over Fiji on Friday night. His hamstring was torn away from the bone in a sickening collision and he may not play again this season.
Wales coach Mike Ruddock confirmed: "The injury needs an operation and Brent is out of action for at least four months, possibly six.
"It's awful news for Brent and his family, as well as the Ospreys and Welsh rugby, who have lost a quality player.
"On the injury front, we are getting a lot more headaches than we would like."
Cockbain, who turns 31 on Tuesday, joins fellow British Lions Gethin Jenkins, Ryan Jones, Dwayne Peel, Tom Shanklin and Gavin Henson on Wales' ever-expanding injury list. As well, three other Wales players - Dafydd Jones, Kevin Morgan and Chris Horsman - limped off during the Fiji match with ankle injuries. Jones and Morgan are unlikely to play against South Africa next Saturday.
The Wales U18 squad spent an emotional day in the drug-riddled townnship of Hout Bay. Hout Bay Warriors President Fred Johannes said the visit was 'the talk of the town' and will dream about the day everyday for the rest of his life.
RGC 1404's new head coach Mark Jones is hoping to build 'something special' in north Wales and is already looking forward to the development region participating in the Principality Premiership for the very first time.
A joint venture between the WRU and Admiral saw hundreds of children enjoy the Admiral Festival of Rugby held at the National Centre of Excellence at the weekend where Welsh internationals Sam Warburton, Scott Williams and Rob Evans were in attendance.
Wll Jones leads Wales U18s into battle this afternoon against Italy where the Welsh side will be seeking to bounce back from their narrow defeat to SA Schools in their opening clash of the U19 International Series
All four regions attended a successful training camp staged last weekend at the WRU National Centre of Excellence. It was a chance for new Wales Women's head coach Rowland Phillips to deliver his key messages to players and coaches as he prepares for the new season.
Wales U18 Team Manager Gethin Watts believes the next couple of weeks will be 'extremely beneficial' to the future of Welsh rugby as his side prepare to take part in the Under 19 International Series being staged in South Africa.
The WRU is searching for 12 new rugby development apprentices following a successful first year of its WRU Coach Core programme. Craig Duncan and Jess Hancock have flourished in the first year of the programme which has given them a real direction in their lives.
The WRU signed TV comedian Rhod Gilbert up to a 'Coaching Children Level 1' course before letting him loose on an U8s side at Whitland Junior Borderers - we went behind the scenes to film the making of 'Rhod Gilbert's Work Experience' see the results here.
Llandovery are aiming to make it three titles in a row in this year's Foster's National 7s being held at BT Sport Cardiff Arms Park on Sunday 28 August. Drovers assistant coach Simon Davies and Lee Rees assess their sides chances
A pioneering strength and conditioning programme has been delivered to more than 8000 boys and girls at hub schools throughout Wales this season, helping to develop stronger, more flexible athletes for rugby and other sports.
The Singha Premiership Rugby 7s Series returns to the BT Sport Cardiff Arms Park on July 22nd when all four Welsh regions go head to head. Scarlets skills coach Dai Flanagan and Blues Elite Performance Pathway Manager Richard Hodges along with current Welsh squad members were at the launch of this season's event