Celtic's sudden propulsion back into the Europa League has precipitated a steep climb in intensity on Thursdays, and there is unlikely to be much let-up when Neil Lennon's side visit Rennes this week (live on ESPN HD from 1730 BST). Frederic Antonetti's side moved up to fifth in Ligue 1 by beating Lorient on Sunday, and the team's rugged spine is built for combat.
In front of the burly centre-back Kader Mangane is the star of the show - Rennes' defensive midfield rock, Yann M'Vila. Those who recall that the notoriously frugal Arsene Wenger was apparently ready to part with upwards of £20 million to get the 21-year-old on board this summer will wonder what M'Vila is still doing in Brittany.
The answer is not only in the French club's own intransigence as they seek to gain top value for their prize asset, but in the player's own mindset. Karim Benzema's shock omission from France's 2010 World Cup squad after an average debut season at Real Madrid has indelibly marked a generation, and M'Vila had no intention of his own national team spot being jeopardised by a transitional year abroad. He pledged to stay and in May signed a contract extension to 2015.
His extraordinary maturity makes it easy to forget that we are dealing with a player barely into his twenties, as Djibril Cisse remarked as he arrived at Clairefontaine after his recent recall to the national squad. "You know, when I made my debut (for France)," he grinned, "Yann M'Vila was 12. I'm not old yet, but still..."
Already it is M'Vila, not Franck Ribery or Benzema, who is the focal point of everything Laurent Blanc is trying to achieve with France. The rise of the pair has been almost inextricably linked ever since August last year, when Blanc gave M'Vila his full debut in the friendly against Norway, his own first match as coach - precisely 360 days after the midfielder had made his first-team bow for Rennes, in a 1-1 draw at Nice.
M'Vila mused a fortnight ago - between the Euro 2012 qualifying double-header with Albania and Bosnia - that he is not "undroppable". Many in France would disagree, ever since that hugely impressive first match in Oslo. Despite his level-headedness, the midfielder himself betrayed recognition of that when he revealed the quiet word that Blanc's assistant Alain Boghossian had with him in the warm-up to the Albania game. "Even if a player is getting away from you, don't grab his shirt," advised Boghossian. A yellow card would have ruled M'Vila out for the final qualifying match against Bosnia, a scenario that neither assistant nor head coach were prepared to countenance.
France may be more recognised for producing towering beefcakes of defensive midfielders, in the mould of Patrick Vieira or sometime-captain Alou Diarra, but M'Vila is part of a nouvelle vague. He stands at a relatively modest 5'11", but along with the likes of Lille skipper Rio Mavuba and even the 18-year-old Manchester United prospect Paul Pogba, relies on snap, mobility and a highly-polished technique.
M'Vila himself has never seen size, or reputation, as an issue. "You can't let yourself be intimidated," he said last year, shortly after his France debut. "There's no pity on the pitch, and I'm not there to have fun. If I'm given an important role, I'll make the most of it." His meteoric rise in the last two years is testament to that, but he has had to work every step of the way.
Coming from a tough suburb in the northern city of Amiens, M'Vila readily admits things could have been very different for him. "There were hardly any kids (in my neighbourhood) who weren't going around stealing things," he told French magazine So Foot in February. "Without football, I don't see why I would have done any better than the others. I stole scooters, and wandered the streets after midnight even though I had school the next day."
Things changed when he moved to the lauded Rennes academy at 14, and now he is already married with two children. When M'Vila bought his first apartment after turning pro, it was in a quiet area away from the bright lights of the city centre, and he invited his two teenage sisters to live with him. His eschewing of the flash translates to his style on the pitch, even if his self-assessment ignores his pedigree. "I never felt the need to dribble, or do ball tricks," he told So Foot. "Not even ball-juggling. I've always loved playing simply - control, pass, mark."
If M'Vila's own doggedness is only to be admired, he owes plenty to the faith of his current coach - and fellow straight-talker - Antonetti. The bluff Corsican's predecessor in the Rennes hotseat, Guy Lacombe, viewed M'Vila as a loose cannon despite his talent. Yet Antonetti gave M'Vila his first-team chance within weeks of arriving at the Stade de la Route de Lorient, and promoted his protégé's chances of a France call-up when M'Vila had barely 20 first-team matches under his belt, to the sniggers of a not-inconsiderable number of journalists.
Antonetti was vindicated when Raymond Domenech called up the teenage M'Vila to the preliminary squad of 30 for the 2010 World Cup. Even if he didn't make the final cut, it was with a justifiable smugness that Antonetti last month described his talisman as "a mixture of great defensive midfielders. He has the understanding of the game of Claude Makelele, the workrate of Patrick Vieira and Yaya Toure's quality of passing. He plays like a player with ten years' more experience."
M'Vila was used sparingly by Antonetti during the Europa League qualifying rounds, and was only a substitute on the last matchday, in the draw against Atletico Madrid. He would not be best pleased to be given a rare breather this week. "I want to play every match," he said last week. "It's like with a pitbull. When you give it something, it grabs it and doesn't let go. And me, when I have something, I don't let it go." Celtic are about to find out just how focussed Yann M'Vila is.