Wales take a gamble on Henson

Centre picked for Sunday's opener against Scotland despite injury concerns

Poor Gavin Henson. It is never simple. Just when it seemed that everything was finally going right for the boy who has always had everything – new baby squawking merrily in the cot at home, new midfield partner even more cheery-faced next to him at work – then along comes another damned injury to threaten all that joy.

It was at the end of Tuesday's training session under the roof of the Millennium Stadium when Henson felt his calf tighten. Yesterday, during the morning session the strain was still apparent, forcing the medics to make further investigations and Warren Gatland to apply an asterisk next to his No 12's name when revealing his side to face Scotland in the Six Nations opener in Edinburgh on Sunday.

"He's missed training and had some treatment this afternoon, there's a day off tomorrow and when Gavin comes in on Friday we'll make a decision," said Gatland. "There's no point risking a big tear that might keep him out for six to eight weeks. If we have to pull him out we will. We won't wait until the day of the match like we did in the autumn series."

Rob Howley will doubtless say Amen to that last promise. On the eve of the first autumn test against South Africa in November, the skills coach informed reporters that Henson, despite an Achilles problem, would, most definitely, be starting only to come back 15 minutes later and make a swift U-turn. The coaching staff's eagerness to see Henson's new midfield partnership with Jamie Roberts may just have had something to do with them taking it to the wire on that occasion and that is understandable.

With respect to Tom Shanklin, who is on the bench and who, in fact, has started 12 times alongside Henson for Wales and has yet to be beaten when doing so – the thought of Henson and Roberts in unison in the midfield is enough to raise the goosebumps in both Welsh and Scottish camps. Gatland, for one, has evidently been tantalised by the prospect for some time and will be praying that Henson is given the go-ahead tomorrow, despite Wales boasting such strength of depth in the centres.

"I think the exciting thing about the two of them is just the size and physicality," crooned Gatland. "Two big men, both over 100kg, both powerful. They looked sharp in training last week. Gavin's got some lovely touches at 12 and Jamie runs some nice lines off him as well. If you're an opposition outside-half you don't particularly want one or both of those coming down your channel."

While Gatland's admiration of Henson has been known ever since he arrived, his equal fondness for Roberts is only now becoming so apparent. Yesterday he dismissed any fears that the bullocking Blue is inexperienced in the outside centre berth and said "I think he'll be a fantastic midfielder." It was Gatland's idea to first try this full-back-come-wing into centre and so far everything he has touched in the last 12 months has turned into Welsh gold. His most staggering transformation, however, has been the one from rank outsiders to firm favourites to win the Six Nations.

Gatland inevitably sought to play down the odds – "we're slight favourites, yes," he said, "but not overwhelming ones" – but did reveal that the players had been gathered to pay close inspection to the bookmaking markets. Shaun Edwards, the defence coach, was detailed to address the squad on and recall his days in rugby league with Wigan and how they responded to being champions the following year. If the Wales players in the starting XV needed any motivation to guard against complacency, however, they only had to look at the Murrayfield bench.

Not only will Tom Shanklin be sitting there but also the so-called dream half-back team of James Hook and Dwayne Peel. And the last named is only on the bus at all because of the knee injury to Gareth Cooper. The Gloucester scrum-half will probably also miss the England encounter on Saturday week; which at least gives Peel a chance to re-emphasise his considerable claims.

Murrayfield teams (Sunday, kick-off 3.0pm)

Scotland: H Southwell (Edinburgh); S Webster (Edinburgh), B Cairns (Edinburgh), G Morrison (Glasgow), S Lamont (Northampton); P Godman (Edinburgh), M Blair (Edinburgh, capt); A Jacobsen (Edinburgh), R Ford (Edinburgh), G Cross (Edinburgh), J White (Sale), J Hamilton (Edinburgh), A Hogg (Edinburgh), S Taylor (Stade Français), J Barclay (Glasgow). Replacements: D Hall (Glasgow), A Dickinson (Gloucester), K Brown (Glasgow), S Gray (Northampton), C Cusiter (Perpignan), C Paterson (Edinburgh), M Evans (Glasgow).

Wales: L Byrne (Ospreys); L Halfpenny (Cardiff Blues), J Roberts (Cardiff Blues), G Henson (Ospreys), S Williams (Ospreys); S Jones (Scarlets), M Phillips (Ospreys); G Jenkins (Cardiff Blues), M Rees (Scarlets), A Jones (Ospreys), I Gough (Ospreys), A-W Jones (Ospreys), R Jones (Ospreys, capt), M Williams (Cardiff Blues), A Powell (Cardiff Blues). Replacements: H Bennett (Ospreys), J Yapp (Cardiff Blues), L Charteris (Newport Gwent Dragons), D Jones (Scarlets), D Peel (Sale Sharks), J Hook (Ospreys), T Shanklin (Cardiff Blues).