England are playing an unusually strong hand against the Barbarians in today's end of season runaround at Twickenham. With three Tests against the Springboks in South Africa starting in Durban on Saturday week, this is a crucial loosener.

True there are one or two thrusting tyros being given a run, such as the Wasps wing Christian Wade and flanker Joe Launchbury, but mostly the changes to the first choices have been forced by injury or the unavailability of the Harlequins and Leicester players involved in yesterday's Premiership final. Dylan Hartley, for instance, is in at hooker after serving an eight-week suspension for biting in England's last match, the otherwise heartening 30-9 rout of Ireland at Twickenham in March.

The Barbarians have a highly capable front row of John Afoa, John Smit and Neemia Tialata, although the perennial question will be how long and hard the invitational side will be prepared to scrummage and maul against an England side with the big bad Boks on their minds.

"We've spoken about this as a launchpad," says Hartley. "Win this game, then we get 18 finalists join the group on Monday, and it's a happy camp when we're flying on Wednesday."

England will use all their replacements and intend to examine some new and overdue attacking options by deploying the London Irish centre Jonathan Joseph alongside Owen Farrell and Brad Barritt in the second half.

"I've compared this past week's training with our first week in Leeds before the Six Nations," Hartley says. "The baseline on our first day's training was brilliant and the accuracy every day has got better. Everyone knows the systems, including the new players coming in."

Hartley's enthusiasm has a different source: two months of frustrating inactivity and the obvious perception that after long, hard years spent disproving a reputation for hotheadness that came with a six-month ban for gouging in 2007, he will be seen as a recidivist for his bite on the little finger of the right hand of Ireland's flanker Stephen Ferris. In fact the Six Nations disciplinary panel chose to ignore Hartley's previous record, effectively treating his slate as clean.

But as the 26-year-old puts it: "It will be easy for people reading the stuff to say, 'Yeah, he's a biter,' even though I've had players come to me and explained they understand the circumstances."

Those circumstances were a first-half ruck in which Hartley had a strong "jackalling" position over the ball and Ferris grabbed him around the neck and head, to try to move him. Ireland's doctor, Eanna Falvey, reported to the disciplinary hearing: "There were three obvious tooth marks from a bite to the middle phalanx of the fifth finger of the right hand."

Or, as Hartley calls it, "the pinky". There was a difference of opinion over that digit. Ferris gave evidence that his finger did not enter Hartley's mouth until Hartley bit him.

"Basically it was his word against mine. It felt like he had something in for me," says Hartley. "You can't lever somebody without gripping them [and] whether it was accidental or by design his hand was in my mouth. I think it was accidental."

It was certainly dental.

"He pulled me, I've bit as a reaction," Hartley says. "Before I could even think about there being something in my mouth, I'd done it."

And he sighs and adds that in his understanding the panel agreed with that version but concluded the bite was still to be punished. "I struggled with that because I had no control over it. It's not like I've gone and bit someone's face or someone's ear, looking to hurt someone. It was purely a reaction to someone's hand in my mouth because I was uncomfortable. I've got that label now."

Nevertheless, while conceding that "the South Africans might see it as a weakness and they could be coming for me", Hartley says the test he will face will be nothing like the "long process of about three years" after the gouging ban. "I've played too many big games now when people have tried and failed to provoke me. Little did they know I was always thinking about it, one step ahead."

The Wales coach Warren Gatland's wind-uppery, referring to Hartley standing up in scrums, was one example in 2011, ridden out triumphantly by the hooker in an England win.

The biting ban ended at midnight on Sunday 13 May, about 31 hours after Northampton had been knocked out of the Premiership play-offs at Harlequins. They could have done with Hartley, in the absence of the suspended Calum Clark and the injured Tom Wood and Courtney Lawes.

"I do feel guilty in the sense that I didn't contribute to Saints' season as much as I wanted," Hartley says. "Though if you look at it in a selfish light, not putting my body through rugby for eight weeks was good. It's like I've been through a pre-season. Jim Mallinder [Saints' director of rugby] insisted I did every first-team training session, every second-team session, and I was the first man up for any community work and school visits. When you're banned or injured your pigeon hole is always full."

He was also enlisted by the stand-in captain, Lee Dickson, to gee the Saints up before matches. "The semi-final at Harlequins was hard," he says. "You're warming up with the lads then it's kick-off and you have to sit and watch. I felt like a fan."

England's tours of South Africa

1972 Played 7 Won 6 Drew 1 Lost 0

1984 P7 W4 D1 L2

1994 P8 W3 L5

1998 P1 L1

2000 P5 W4 L1

2007 P2 W0 L2

England B Foden; C Ashton (both Northampton), B Barritt, O Farrell (both Saracens), C Wade (Wasps); C Hodgson (Saracens), L Dickson (Northampton); M Stevens (Saracens), D Hartley, P Doran-Jones (both Northampton), M Botha (Saracens), T Palmer (Stade Français), T Johnson (Exeter), P Dowson (Northampton, capt), C Fearns (Bath). Replacements L Mears (Bath), M Mullan (Worcester), J Launchbury (Wasps), J Gibson (London Irish), R Wigglesworth (Saracens), J Joseph (London Irish), A Goode (Saracens).

Barbarians M Muliaina (New Zealand); P Sackey (England), C Laulala (New Zealand), M Tindall, I Balshaw (both England); S Donald (New Zealand), R Lawson (Scotland); N Tialata (New Zealand), J Smit (South Africa, capt), M Chisholm (Australia), A van Zyl (Stade Français), E Joubert (Saracens), J Beattie (Scotland), A Qera (Fiji). Replacements B August (France), D Jones (Wales), P Taele-Pavihi (Samoa), R Lakafia (France), J Fillol (Stade Français), F Contepomi (Argentina), S Tagicakibau (Samoa).

Referee J Lacey (Ireland).