Tom Wood's elevation leaves resting Chris Robshaw at risk

Chris Robshaw will definitely be included in England's elite squad when the red-rose coach Stuart Lancaster makes his hard calls for next season, but that may be the extent of the good news for the man who led the national team to a famous victory over the All Blacks and took them to the brink of a Grand Slam. He has been given no guarantees on the captaincy and may soon find his place in the team under threat – a heavy price to pay for a summer's rest he did not want in the first place.

The Harlequins flanker was left out of England's 32-man party – a group featuring 11 uncapped players – for next month's Test series in Argentina. Tom Wood, who might have beaten Robshaw to the captaincy in early 2012 had he been fully fit, will shoulder the burden against the Pumas, and the Northampton back-rower's many supporters expect him to make an outstanding job of it. Indeed, they believe he will make himself indispensable.

Three years ago, the England captain Steve Borthwick missed a summer trip to Australia and was then drummed out of international rugby by Martin Johnson, the manager, in one of the more ruthless selectorial acts of the professional era. Lancaster is no Johnson: he has no intention of treating his most senior player with contempt. But if Wood delivers on the leadership front in South America and someone makes a name for himself in the breakaway role, all bets will be off. Robshaw is fortunate that the Saracens newcomer Will Fraser injured himself towards the back end of a Premiership campaign in which he emerged as the brightest young hunter-gatherer in the English game. He might have made life really difficult for the incumbent.

As it is, England will travel with the Exeter back-rower Tom Johnson, whose star has faded in recent months, and the uncapped Matt Kvesic, who is in the process of leaving Worcester for Gloucester and may not fulfil his obvious potential until he finds his feet at Kingsholm.

Lancaster did not leave Robshaw isolated: such familiar figures as the wing Chris Ashton, the centre Brad Barritt, the stand-off Toby Flood and the scrum-half Danny Care joined him on the "rest and recuperation" list. While Barritt and Care can confidently expect to join Robshaw in the top-tier party due to be named in late July, Ashton and Flood cannot be so sanguine. The brat-packers are hot on their heels and could easily overtake them.

Freddie Burns of Gloucester, by common consent the No 10 most likely to spark England's dormant attacking game, will start the first Test against the Pumas in Salta on 8 June and has the ability to wrest the shirt from the Lions-bound Owen Farrell. By the end of the tour, there may be a fresh and exciting look to the back-three combination as well. Christian Wade of Wasps, Jonny May of Gloucester and Marland Yarde of London Irish are all on the trip, having played some startling rugby in recent months.

"People have been talking about 'new Jason Robinsons' and I can certainly see the comparison in Wade's case," said Lancaster. "The way he beats people, the buzz he creates around a ground… When I look at this squad, I'm probably most excited about the wing options. All of them have pace. All of them have the X-factor."

Yet the coach knows that he could play David Campese on one wing and Jonah Lomu on the other and still not trouble the scorers if things go wrong up front. Which is where Dave Attwood, one of English rugby's lost souls, comes in. The Bath lock won a couple of caps ahead of the 2011 World Cup and looked a sure bet for a big role in that tournament. That changed when he missed important matches through long-term suspension and it has taken him the best part of two years to re-establish himself as a Test lock in waiting.

"I spoke to rugby directors around the clubs ahead of this selection and the one player Gary Gold at Bath really pushed was Attwood," Lancaster said. "He talked about his mindset, his professionalism, his work-rate. We all know about his physical attributes: he's a genuine bag man and we don't have many second-row forwards like that. Now that he's also running the line-out at Bath, we want to see him transfer everything he's doing to the international scene. This is a great opportunity for him to break into the Test team, and that's the truth."

England squad: Touring party

For summer matches against the Barbarians, Uruguay and Argentina.

Fixtures 26 May v Barbarians at Twickenham; 2 June v South American XV at Montevideo; 8 June v Argentina at Salta; 15 June v Argentina at Buenos Aires.

Forwards D Attwood (Bath), R Buchanan (Harlequins), C Clark (Northampton), A Corbisiero (London Irish), P Doran-Jones (Northampton), T Johnson (Exeter), M Kvesic (Worcester), J Launchbury (Wasps), C Lawes (Northampton), J Marler (Harlequins), B Morgan (Gloucester), D Paice (London Irish), E Slater (Leicester), H Thomas (Sale), B Vunipola (Wasps), R Webber, D Wilson (both Bath), T Wood (Northampton; capt).

Backs M Brown (Harlequins), F Burns (Gloucester), L Dickson (Northampton), K Eastmond (Bath), B Foden (Northampton), A Goode (Saracens), J Joseph (London Irish), J May (Gloucester), D Strettle, J Tomkins (both Saracens), B Twelvetrees (Gloucester), C Wade (Wasps), R Wigglesworth (Saracens), M Yarde (London Irish).

IRB engages new trial rules to clean up scrum

The International Rugby Board will make yet another attempt to clean up the scrum, perhaps the biggest problem area for the sport, with a worldwide trial starting in September.

Tired of constant collapses and penalty awards, the authorities have agreed to test a new engagement process in which props will bind on their rivals' arms before the scrum is set. They believe this will place a premium on technique while minimising the risk of injury. If successful, the system will be formally adopted in time for the 2015 World Cup.

Chris Hewett