The Gunners star believes that the North Londoners are better prepared to compete in clashes with the top teams.
The North London side have been accused of losing clashes with fellow title-chasers, with a number of hefty defeats to the likes of Chelsea, Manchester City and Liverpool in the 2013-14 campaign specifically sticking the memory.
However, signs were last season that Arsene Wenger’s men had turned a corner, with a 2-0 win away to City in particular showing that the Emirates Stadium outfit could mix it with the big boys.
A 1-0 win over Chelsea in the Community Shield at the weekend, ending Wenger’s abysmal personal record against Jose Mourinho, is seemingly another sign that the Gunners should be taken seriously in the title race this season.
Oxlade-Chamberlain, who netted the only goal of the game against the Blues, feels that Arsenal’s mentality has now improved.
"Ever since I’ve been at Arsenal, we’ve had numerous quality players and the whole squad had been very strong," Oxlade-Chamberlain said, according to FourFourTwo.
"It just seemed that in the big games we came up short sometimes and you wonder why.
"The mentality going into those games was definitely a big thing. Since I’ve been here we’ve steadily got better at that, especially last year.
"A game like that against Chelsea is always important because they are a good side and it’s great to come away with some silverware.”
Arsenal will hope to start the new season strongly, with their pre-season form suggesting that the North Londoners mean business this term.