With Thomas Vermaelen a long-term injury absentee, the pair have a chance to forge a partnership at the heart of Arsene Wenger's back line and Koscielny feels the signs are positive. The Frenchman has not always cut a confident figure since his arrival from Lorient last year, while Mertesacker - a deadline day signing from Werder Bremen - still has questions to answer over his lack of pace in the Premier League. But, since Koscielny's return to full fitness they have teamed up for back-to-back victories, against Sunderland at the weekend and Marseille on Wednesday night, and are eyeing a third when Stoke visit the Emirates on Sunday. Koscielny, for one, is happy with how their understanding is developing. "Personally, things are getting better and better with Per," he told Arsenal Player. "He is a very experienced player, he is an international player, he knows what the very high level is about. We know that the English league is very different than the other European leagues and there is always time to adapt. Soon he will become a key player in this team." Wales captain Aaron Ramsey was the scorer of the only goal at the Stade Velodrome, a 92nd-minute winner that left the Gunners top of their Champions League group after three unbeaten matches and favourite to progress as winners. He acknowledges his side's domestic form has not been as strong - they lie 10th after losing half of their eight league outings - but Ramsey is hoping to put that right in the coming weeks. "We haven't had the greatest of starts to the season but, hopefully, we've turned the corner by getting a few wins on the bounce and we want to keep it going," said the midfielder. "There is no question our confidence is returning now. "In past games, we could have defended better as a team and it was a bit harsh to blame it on the defence. I thought they did magnificent in Marseille. "We've done well in Europe so far so we just want to keep the momentum going in the league," he continued. "It is important to keep that momentum going and, hopefully, get another win at the weekend." Arsenal have injury concerns over Kieran Gibbs, who missed the Marseille clash with a stomach muscle strain, and fellow full-back Carl Jenkinson who was forced off after an hour with a knee complaint.
