Arsène Wenger intends to push ahead with his move for the Real Madrid midfielder Nuri Sahin only if Alex Song were to leave Arsenal. The manager, who was finally able to announce the signing of Santi Cazorla from Malaga on Tuesday morning, has grown irritated with Song over the midfielder's desire to explore his transfer market options.

Wenger has pursued Sahin and there has been a confidence behind the scenes at Arsenal that the Turkey midfielder is attainable, initially on a season-long loan. José Mourinho, the Madrid manager, said last week that he would not stand in the player's way if he wanted to join Arsenal.

But Wenger appears to have lined up Sahin as a contingency in the event of Song's departure. Song is aware that a clutch of Europe's leading clubs, including Barcelona, have made enquiries about him, on the back of his encouraging season last time out, when he developed the more creative side of his game and he wants to listen to what they have to offer.

There have been no firm bids as yet but Wenger has come to consider the merits of selling Song for £15m or more, particularly if he could bring in Sahin to retain his numbers in midfield. Wenger has said that he will be without Jack Wilshere until October, at the earliest, as the midfielder fights to return from the stress fracture to his foot that kept him out for the whole of last season.

The signing of Cazorla had been heavily trailed, largely because the attacking midfielder passed his medical at the club last Thursday. He even accompanied the Arsenal squad to their training camp in Germany on Monday. But Wenger spoke of his delight at what feels like a significant piece of business after the final kinks were ironed out with Malaga.

Arsenal claim that the fee for Cazorla is a bargain £12m, although the figure is likely to rise when performance-related targets are met. The 27-year-old follows the strikers Lukas Podolski and Olivier Giroud to the club; all three stand to make their debuts in Sunday's friendly at FC Koln.

"There's a very good squad here and we want to fight for titles and win titles," said Cazorla. "The club has made a big step to sign players to have a better team and meet the expectations of the fans. I'm very happy to be here, Arsenal are a huge club. I hope to win trophies here, that is what I want."