Arsène Wenger believes Arsenal are steadily recovering their poise after a desperate summer, which saw "half the dressing room wanting to leave". Despite a traumatic start to the campaign the Arsenal manager remains confident his team have the time and ability to reclaim a place in the Premier League's top four.

The 2-1 victory over Sunderland on Sunday restored Arsenal to the top half of the table, only six points off fourth-placed Newcastle, with a Champions League group game at Marseille to come on Wednesday. Wenger conceded the top two, Manchester City and Manchester United, are too far away to catch and suggested players have joined the current league leaders less for the chance to win trophies but rather more for the salaries City are prepared to offer.

Wenger, who lost Gaël Clichy and Samir Nasri to the Etihad Stadium this summer, was asked to reflect on comments made by his former midfielder Emmanuel Petit last week in which he suggested sales were "killing" the club.

"No, it's not that [players have to leave to win titles]," said Wenger on the French radio station RTL. "The problem isn't that. Frankly, if you compare what Manchester City have won in the past and what Arsenal have won, then you don't go to Manchester City to win titles. Players go to Manchester City because they pay much better than Arsenal.

"They are a force clearly, because they have exceptional financial clout, so it's not surprising what they've done. Look at Paris Saint-Germain. They have more money than anyone else in France and they're top of the league. There's always a financial logic behind who ends up being successful in any league. If Barcelona or Real Madrid paid three times less than Malaga, players would go to Malaga. That's always the case. It's as simple as that. So when a player has the choice between two clubs who have the same ambitions, if he can earn three times as much at one club, he'll go there. That's logical."

That last response was given in direct relation to a question posed on Nasri's defection, with the France international having joined Cesc Fábregas in leaving the Emirates over the close season. "It was a very difficult summer because half the dressing room wanted to leave," said Wenger. "You're preparing for a season where you don't know who's going to come in, the players who are staying are asking themselves what's going on at the club, you've got a pre-season tour of Asia. It was extraordinarily difficult. What saved us is that we're a club that are extremely solid and united. Other clubs would surely have gone to pieces in those circumstances.

"What people forget is that we lost three key players because we've also lost [Jack] Wilshere. Three who were important in our midfield. Nasri, Fábregas and Wilshere have all been lost and they were the basis of our midfield last season. We've had to reconstruct our midfield entirely because Wilshere won't be back until January. Still, we've disappointed this season so far, given what's expected of us, but I think we're on the up again. The problem is you can only climb the table slowly. We're not too far away in terms of points from fourth place. We're too far away [12 and 10 points] from the top two."

Arsenal are yet to secure Robin van Persie on new terms at the Emirates. The current captain is into the final two years of his current deal, prompting fears of a repeat of the Nasri scenario.

"For me being professional means that right up until the last day you are at a club you give 100% to that club," added Wenger. "Today, two days before we play at Marseille, I'm not asking myself whether Van Persie is going to extend his contract in 18 months' time. For me what is important is that he plays well for us on Wednesday. After that the next match. That's how I think. He's scored 28 goals in 34games, so they're exceptional statistics. He's got a contract for another 18 months and he's a man who is attached to our club. I'm not especially thinking about losing him."