Arsene Wenger is expecting to see the best of Alexandre Lacazette as the striker returns from a knee injury in time to lead the line in Arsenal's Europa League quarter-final clash with CSKA Moscow.

The 26-year-old France international did not hit the ground running at the Emirates Stadium following his move from Lyon last summer for a then club-record fee.

Lacazette scored nine goals in 29 appearances before requiring surgery on a niggling knee problem following the 1-0 defeat to north London rivals Tottenham on February 10.

That was the only time he was able to partner deadline-day signing Pierre-Emerick Aubameyang, who was purchased for a higher fee in January leading to questions over Lacazette's long-term prospects at Arsenal.

The pair were reunited in attack against Stoke on Sunday as Lacazette returned from his surgery to score off the bench in a 3-0 win, Aubameyang unselfishly passing up the chance of a hat-trick to allow his team-mate to mark his comeback with a goal.

Arsenal now face CSKA knowing that winning the Europa League is their own realistic chance of securing a Champions League return - given they are 13 points adrift of the Premier League top-four.

Aubameyang is cup-tied in Europe so, in Lacazette's absence, Danny Welbeck has been the only recognised experienced striker available to Wenger.

The England international hit a brace to see off AC Milan in the last round but is likely to lose his place to Lacazette on Thursday, with Wenger believing his summer recruit is ready to start firing.

"It is good to have him back because it give us different opportunities," he said of Lacazette.

"Danny is more a guy who goes behind, whereas Lacazette is more  combination play so to have both options is important.

"I realise now when I see him in training that he was not himself for a while. That explained why scoring goals dried out - he was always adamant, 'I am okay, I am okay', but players are like that.

"It was not dramatically different before. He was a good player. But I think in the last seven or eight games he played, he was not completely free with his knee.

"Unfortunately, in our job you need your body and unfortunately when you are not 100 per cent you cannot play well."

With almost all hopes of Champions League football returning to the Emirates Stadium next season hanging on Europa League success, Arsenal fans will have to heed the warning issued by Wenger on the eve of this quarter-final clash.

"I believe the level of the Europa League has gone up," he said.

"If you look at the teams who were involved and even some teams who went out like Dortmund, it is more difficult than ever before - especially as there is more focus on it as well since you had a place for the Champions League.

"Everybody thinks, in some big leagues, it is more and more difficult to be automatically in the Champions League so it becomes more focused on the Europa League."