Pires, who still trains regularly with Arsenal, stuck up for Ozil following criticism of the Germany playmaker for a number of below-par performances for the club.
"Ozil is a warrior who wants to win something," Pires told German publication Bild.
"To me, he seems so angry about the fact that Arsenal hasn't put together the team with which he can make a difference.
"They only spent money on Alexandre Lacazette. That's not enough to compete for the top spots."
Arsenal currently sit sixth in the Premier League table, having lost three of their opening eight games of the season.