Arsenal's switch to 4-3-3 at the start of the season placed increased importance on the midfield area, and several players were able to step up to the plate.
After starting with Denilson sandwiched in between Song and Fabregas, an injury forced Wenger to play Diaby and the Frenchman never looked back, showing an improvement in his positional + defensive discipline, dribbling, passing and goalscoring to become the perfect box-to-box player for Arsenal's system. Denilson, while a tidy and intelligent player (not to mention an expert long distance shooter), fell down the pecking order as Diaby's dynamism was preferred in the middle.
Samir Nasri was a different case altogether. For most of the season he had to make do with a spot in the right of Arsenal's attack and struggled to exert influence on matches. After Fabregas' injury and his switch to a more central role, he was able to show what he was capable of, most notably in the 2nd leg of the Champions League quarter-final against Porto, where he capped an excellent performance with a wonderful solo effort.
Next season Diaby must build on the excellent progress he's made this season, while Denilson and Nasri need to step it up if they're to make the first XI.
