Six Nations 2013: Alun Wyn Jones battles Sam Warburton to lead Wales in title decider against England

Second-rower emerges as a major threat to No 7 reclaiming the armband in Cardiff

Wales will definitely be forced into a change of captain for this weekend's title-deciding Six Nations set-to with England at the Millennium Stadium, but it is not a foregone conclusion that Sam Warburton, once the red-hot favourite to lead the British and Irish Lions in Australia this summer, will reclaim the honour. The lock Alun Wyn Jones has emerged as a serious challenger to Warburton after his outstanding performance against the Scots in Edinburgh four days ago.

Warburton, struggling for fitness at the start of the tournament, lost the captaincy to his fellow flanker Ryan Jones after the opening-round defeat by Ireland, and Jones promptly led the reigning champions to an unexpected victory in France. But the universally popular Ospreys forward broke a bone in his shoulder midway through the Murrayfield encounter and will be out of the game until May.

"The captaincy is up for discussion," Robbie McBryde, the Wales assistant coach, said. "We are not under any pressure to make decisions at the moment. We will take our time and make sure the decisions are right. We want to be spot on."

With Wales needing only an eight-point victory to retain the Six Nations title and England chasing a first Grand Slam since their World Cup-winning year of years in 2003, this is the last fixture on earth to be in need of additional frisson.

But Warburton's contest with the England captain Chris Robshaw has an obvious Lions dimension to it, and if the Cardiff Blues player regains the Wales captaincy against the new favourite to lead the British Isles squad to Wallaby country, all eyes will be on the battle of the breakaways.

Rob Howley, Wales' interim head coach, is also balancing the rival claims of two loose-head specialists: the experienced Lions Test front-rower Gethin Jenkins and the strong-scrummaging Bath prop Paul James. Jenkins started the round-three game in Italy and played an excellent hand at the set-piece before picking up a calf injury and giving way to his understudy. For his part, James was influential in wrecking the Scottish scrum last weekend. It will be the tightest of tight calls.

Meanwhile, the England camp have continuing issues in the second row department. Joe Launchbury, an engine room revelation in recent matches, picked up a nasty elbow injury during the narrow victory over Italy on Sunday and did not train today.

If he misses out – Andy Farrell, the England attack coach, tried to strike an optimistic note but could not guarantee his readiness – the red rose medical staff will find themselves working overtime on Launchbury's fellow locks Geoff Parling and Courtney Lawes, both of whom have injury problems of their own.

"We'll give Joe some time," said Farrell. "The injury is not as bad as we had first feared and he's improving. He now has a smile on his face when he's walking around the hotel corridors." Mouritz Botha of Saracens trained with the England squad and will stay in camp as cover.