Robert Pires has described Arsenal midfielder Mesut Ozil as "a warrior who wants to win something" but believes he is frustrated by the club's lack of summer signings.

Ozil has been criticised after some below-par performances this season, but Arsenal great Pires defended him in an interview with Sport Bild.

"Ozil is a warrior who wants to win something, and currently he makes the impression that he's annoyed Arsenal have not assembled a squad which can win something," he said.

"They only spent money on Alexandre Lacazette. That's not enough to compete for the top spots."

Arsenal suffered another setback with a 2-1 loss at Watford on Saturday, leaving them nine points behind Premier League leaders Manchester City.

Mesut Ozil is 'annoyed Arsenal have not assembled a squad which can win something.' John Walton/PA Images via Getty Images

Their unconvincing start has led to questions about the decision to hand Arsene Wenger a new two-year contract in the summer, but Pires -- who still trains regularly with Arsenal -- is backing the manager.

"It's incredibly difficult to consistently remain at the top in England," he said.

"But I still believe in Arsenal and first of all in Arsene Wenger. I think it's right he penned a new two-year deal."

Pires also talked about the growing strength of Ligue 1, where Paris Saint-Germain broke the world transfer record to sign Neymar from Barcelona this summer.

He said: "Everyone benefits from a strong Paris Saint-Germain -- the club itself, the French league and also the Champions League.

"In Real Madrid, Barcelona, Juventus and Bayern there have been the same title contenders year in, year out. Paris joins them now. That's good."