You need to be a tough cookie to play rugby.

"My strangest experience was being tackled by a spectator dressed as a Viking when playing in the Varsity match. The horn on the helmet he was wearing gave me a dead leg," recalled Ben Ryan, the head coach of England's sevens side.

Compared to the batterings and clatterings his players have received over the course of the current HSBC Sevens World Series , the 41-year-old got off lightly. Two broken legs, one cruciate ligament rupture and a dose of concussion? It's the kind of damaging dunts Evel Knievel used to rack up on a regular basis.

But like the star spangled stuntman, Ryan's side have picked themselves up and dusted themselves down. This weekend at Scotstoun, they could go some way to leaving Scotland on the casualty list in what will be a crucial round of matches in the Emirates Airline Glasgow Sevens.

The hosts are fighting for their world series status and need a strong showing on home soil to preserve their place at the top table. England sit safely enough in 10th spot in the rankings, but, like the Scots, they have endured something of a rollercoaster campaign since an injury-blighted opening weekend in Australia during which they lost two key squad members, Chris Cracknell and Mat Turner.

"It was as bad a start as we could have had and those first few events set us back hugely," Ryan said. "We seemed to be down to eight players before we'd even taken a breath."

Those early wounds were soothed by victory over Kenya in the final of the New Zealand leg of the series in February as the recovery process gathered pace.

Whether England, beaten in the final of the Glasgow Sevens event by the All Blacks a year ago, dish out a crippling blow to Scotland's hopes of avoiding relegation remain to be seen but Ryan would not delight in their demise. "It's a shame really as I don't want anything to do with Scotland not retaining their core status," he said ahead of the countries meeting in a group which also includes Portugal and the reigning champions, New Zealand.

"Like us, they had a difficult start but they've picked up the pace again and strung together some good performances. They shouldn't really be where they are."

Cross-border clashes are frequent on the sevens scene and while England have had a couple of hefty 30-point victories this season, the Scots can take heart from a 14-5 win the last time the two sides slugged it out, in Hong Kong in March.

They may be auld enemies but Ryan harbours a strong respect and admiration for his northern neighbours.

"The fact we play each other quite a lot doesn't dilute the rivalry at all," he added. "Yes, we travel together, we spend time off the field together, we have to pick each other up at times as we both appreciate each other's difficulties on and off the field.

"But when we get on that pitch, it's as hard fought as you can imagine. It's the usual old rivalry. Scotland have a huge amount to play for and all I can say is there will be a lot of twists and turns in our group over 24 hours."

Twists and turns are very much part of this game, of course, and in an increasingly competitive environment, Ryan knows teams cannot afford to stand still.

Since taking over the England reins in 2007, he has witnessed fairly rapid development both on and off the park. "When I came in six years ago there were only three or four teams that would win," he said. "It's still maybe five or six that have won titles now but to get to the semis and finals is so much more difficult.

"It's like playing six cup finals over two days with no respite. Off the field the stadiums are filling up far more quickly than ever. My first year at the London Sevens, we got 25,000 over two days. You can add another 100,000 on to that now."

With sevens rugby set for a debut in the 2016 Olympics this global growth is set to continue but Ryan is concerned some nations could be left to wither on the vine if they lose their core status on the world rankings and are forced to guddle about for invitations and limited competitive action elsewhere

"We have to be careful we don't just go off at 100 miles per hour and ignore the very important signposts along the way," he said. "If there is relegation we have to think about the consequences. We have to put in place a structure to protect teams that are investing. They can't just drop off into the abyss."