Two seasons ago they were the improbable champions, the club who allowed others to dare to dream, who briefly led to debates as to whether the Premier League had been changed forever, before that fairy tale took a twist.
Leicester struggled, manager Claudio Ranieri was sacked and, despite an exciting Champions League campaign, they were recalibrated under Craig Shakespeare.
Still, they arrive at the Emirates as a solid proposition. A good team reinforced with big signings: 25 million ($44.6m) for Kelechi Iheanacho from Manchester City, 17m for Hull City's Harry Maguire and 12.5m for Sevilla midfielder Vicente Iborra. And if they lose Riyad Mahrez to Roma, they will do so under their own terms, having already rejected three bids from the Italian club.
It means that if they were to draw, or even win, at Arsenal it would be no surprise and it might set the tone for another unpredictable campaign in which we glory at the excitement of the Premier League. Arsenal, however, cannot contemplate another opening-day defeat. Not after losing at home in their past two campaigns - against West Ham United and Liverpool - which set the tone for those seasons and the toxicity that corroded the club. Wenger's future has been resolved with a two-year deal and there was a skip in his step in the Community Shield when his side beat Chelsea. But there always is until the action really begins.
There will be no Alexis Sanchez tonight, an abdominal injury is genuine, and while the signs are that Arsenal do mean it when they say he is not for sale, what kind of player will they have in the final year of a contract that he would prefer not to be held to? The same goes for Mesut Ozil.
And while Arsenal have spent a club record fee for Lyon striker Alexandre Lacazette, for a sum up to 54m, so have their title rivals (Spurs apart) in a summer during which Premier League spending, with three weeks of the window left, has already gone through last summer's 1 billion total.
Chelsea broke their transfer record, signing Alvaro Morata for up to 70m, United spent even more with 75m-plus on Romelu Lukaku, while City have paid out more than 200m.
Liverpool have broken their record to bring in Mohamed Salah, for 37m, and wanted to break it further with Naby Keita from RB Leipzig - unsuccessfully offering 66m - while resisting the 90m Barcelona are offering for Brazilian Philippe Coutinho.
Wenger, when asked whether this season will be the most difficult to win the league, added: "Yes. Because look at what City have done. They have been spectacular in the transfer market. Man United as well. And it's not finished. Chelsea have bought Morata and have not lost [Diego] Costa yet. And they will certainly buy more."
Deliciously, most of those clubs - and their "Hollywood" managers, to borrow the line from Everton's majority shareholder Farhad Moshiri - must do better.
The focus will fall sharply on Manchester, where City and United must both be in contention to win the title, but it will also remain sharp in London. Startingtoday in N5.
All of the managers in charge of those Magnificent Seven survived off-season - four of them had completed their first season - but it is difficult to see that being so next year.
Let the games - and the pressure, the drama, the controversy but, above all, the football, begin.
