Wenger, whose team open their campaign at Everton on Saturday, told reporters Arsenal's young squad had improved greatly in the last year.
"We have developed and we are young - and why are we not better now in August than we were in March? I believe we are stronger physically and mentally after a lot of hard work by everyone," the Frenchman said on Friday.
"Yes, we have lost two good, great players in Kolo and Emmanuel, but we have bought Thomas Vermaelen and we have Eduardo back and I think he is a great player.
"And don't forget we have also others like (Nicklas) Bendtner, (Carlos) Vela and (Theo) Walcott and they are all strikers."
Arsenal finished fourth last season and Wenger said that because of the club's limited transfer activity in the close-season, it would be even more rewarding for him and the team if they were able to win the league
"If we can do it, in a different way, by being loyal to our system and style, it will be very satisfying," he said.
"We don't know how strong Manchester United, Liverpool and Chelsea are going to be, but the target is always 82 points if you want to win the championship and in a league of this quality that means you have to win 25 games.
"For Diaby and Walcott, it is only days before they come back," Wenger said. "I expect Diaby ready for Tuesday. Walcott, I am not so sure."
