Wenger's side left Russia two weeks ago furious at the controversial nature of a 1-0 Champions League defeat against CSKA Moscow that has made their path to the second round more difficult than anticipated.

Arsenal's French striker Thierry Henry had more reason than most to feel aggrieved after he had a goal disallowed in the closing minutes when the referee ruled he had controlled the ball with his hand before scoring.

Television replays showed that Henry's strike was perfectly legitimate and he was fiercely critical of the decision after the match.

Henry and company have a chance to put the record straight on Wednesday when Group G leaders CSKA visit London for the return meeting at the Emirates Stadium.

But Wenger is disturbed by Arsenal's recurring habit of suffering costly lapses of concentration.

Three times this season they have been held to 1-1 home draws by Premiership opponents who have taken advantage of a mistake and then clung on for a point as Arsenal made heavy weather of breaking them down.

Everton were the latest team to frustrate the Gunners on Saturday and Wenger knows his side need to develop a killer instinct quickly if they are to succeed in the Premiership and Champions League.

Wenger said: "Of course I'm concerned about the points we've lost because we have outstanding away form. We won away at Reading, but at home because we are not in the game at the start, or really focused on set pieces, we shoot ourselves in the foot every time.

"We've still not lost here (at Emirates Stadium) and I feel that had we been 1-0 up we would have had an outstanding game against Everton.

"But we made it difficult for ourselves and we have a responsibility. You can always concede a goal, but not like that. If you watch it again we could have cleared that ball easily.

"Let's say we have thrown six points away at home. We could have at least won four of them."

CSKA are closing in on another Russian Premier League after opening up a four-point lead at the top of the table with a win against Rostov on Saturday.

The Russian club's goalkeeper Igor Akinfeev believes his side will seal a place in the Champions League knock-out stages if they can take three points from their next two matches.

He said: "It is too early to celebrate because we still have a game in England and then a home match against Porto. But if we get three points from these, then I think our job is done."

However a win against CSKA would put Arsenal, runners-up in the competition last season, back on top of a group also featuring Porto and Hamburg.

But they may be without right-back Justin Hoyte after the right-back limped out of Saturday's match against Everton.

Togo striker Emmanuel Adebayor is unlikely to recover from a thigh strain in time to feature, but Wenger expects to name Gael Clichy and Philippe Senderos in his squad after stepping up their recoveries from long-term injuries.