Arsenal boss Arsene Wenger admits he has been left surprised by Samir Nasri's impressive start to his career at Emirates Stadium.
The France playmaker joined the Gunners this summer from Ligue 1 outfit Marseille for a reported fee in the region of £12million.
Nasri has netted three goals this season, including a vital strike against Everton on Saturday that sparked an Arsenal comeback
Wenger told the club's official website: "I didn't count Nasri in here for the first six months of the season, like I do for everybody we buy at such a young age.
"When you look at the impact he had already here you can say he's ahead of what I planned for him.
"He's 21, goes from France to England, and I must say I'm quite pleased with his attitude and his performances.
"He's doing extremely well and he is already becoming an important player for us and that is why you do not want him to get injured."
Wenger also confirmed that Nicklas Bendtner (ankle) and Johan Djourou (concussion) are available for Tuesday's UEFA Champions League clash at Fenerbahce.
He said: "From Saturday, we have Nicklas Bendtner back in the squad and Johan Djourou is available again. But we don't have Kolo Toure.
"(William) Gallas and (Bacary) Sagna are out but they are not long-term and could be back in the squad for Sunday."