London :Arsene Wenger's pleasure at seeing Arsenal progress to the Champions League knockout stage has been tempered by injury blows to two crucial defenders ahead of Sunday's pivotal English Premier League tussle with Chelsea.
The Frenchman was angry at seeing Kieran Gibbs, the left-back, sustain a broken first metatarsal in his left foot after a poor challenge from Standard Liege's Eliaquim Mangala in the dying moments of Tuesday's group game at the Emirates stadium.
Gibbs collapsed in agony and was immediately taken to hospital, where x-rays confirmed Arsenal's worst fears: he will undergo an operation on Wednesday morning and is expected to be out for at least two months.
That alone would have been a grievous blow, as Gael Clichy, the Gunners' regular left-back, is currently recuperating from a back injury.
But Wenger's frustrations were compounded by seeing William Gallas, the France defender, fail to re-emerge for the second half due to ankle and eye injuries, the latter sustained in a collision with Andrey Arshavin, his own team-mate.
Gallas' concerns are not believed to be as serious as those of Gibbs, but he is still unlikely to feature against Chelsea, his former club, at the weekend. That represents a devastating blow to Wenger, who cannot contemplate defeat against the west Londoners if he hopes to keep his league title ambitions alive.
Arsenal's defence can be notably soft-centred at the best of times, but stripped of Gallas - arguably their most impressive defender this season - and their two most senior left-backs, it appears even more susceptible.
Carlo Ancelotti, the Chelsea manager, must already be relishing the trip across London.
Wenger's consolation on Tuesday came in seeing his side march into the last 16 of the Champions League for the seventh consecutive season, a record in which he takes justifiable pride.
The performance that took them there was not exactly polished, with Arsenal spurning numerous chances and gifting Standard several opportunities, before goals in the final eight minutes of the first half from Samir Nasri - his team's stand-out performer by some distance - and Denilson killed off the Belgian resistance.
"I'm pleased, because this competition is not easy," Wenger said. "We were favourites in this group, which was normal. So we just did the job.
"I believe we can go further than ever before in this tournament. believe yes. But there are two competitions in the Champions League: one is a championship, one is a cup.
"We move into the cup stage now, and that's very different psychologically. Every minute now becomes important. But we have been consistent and that is pleasing."
For Standard's manager, Laszlo Boloni, this was a chastening evening which had a sour postscript in the red card awarded to midfielder Mehdi Carcela-Gonzalez, dismissed for thrusting his head into Fabregas' face.
Boloni was furious with the 20-year-old and admitted he had given him a severe dressing-down in the aftermath.
"I spoke to him, you can be sure of that," he said.
"The lack of respect for his team-mates and his coaching staff makes me very angry, because we have put a lot of effort into him. He has to learn that the team is more important than his own stardom.
"The players can do a lot better. Maybe they need to be more focussed and concentrated. Maybe they lacked a bit of humility today, so the result was deserved. We gifted Arsenal their goals and didn't make them work hard enough, which was disappointing."