Into its 40th edition -- and 19th under the AFC Champions League brand -- Asian football's premier club competition has been unrecognisable this year.
And that is not just because the expanded format increased the numbers to 40 competing teams across ten groups.
Which, in itself, has prompted fans and experts alike to reach out for old math textbooks and flip to the permutations chapter. Apart from the ten group winners, an additional six best-performing runner-up teams now also advance to the knockout round.
Anyone unfamiliar with group stage football that comprehended that line deserves a pat on the back.
If things were not already complicated enough, the coronavirus pandemic forced the competition to scrap the traditional home-and-away format in favour of centralised host venues.
Like everyone else, players can no longer look forward to the annual trips to Japan and South Korea.
As the ACL East Zone kicks off tonight, with the West group stage having already concluded in May, imagine if this is only the tip of the iceberg in what is shaping up to be the strangest year in tournament history.
The continuing pandemic has wreaked havoc with fixture schedules all across Asia and is the reason why the competition will have a strange feel this year.
For the first time since they were admitted into the Asian Football Confederation as a member association in 2006, no Australian teams will feature because a schedule conflict with the A-League's finals series forced Sydney FC, Melbourne City and Brisbane Roar to withdraw.
While the A-League's representatives have not enjoyed the best of fortunes in the ACL in recent times -- Melbourne Victory's last-16 appearance in 2020 being the first of any Australian side in four years -- they always had the potential to be in the mix. The decision to pull out also robbed Melbourne City of their tournament debut.
Two-time champions Guangzhou FC also have similar woes with the Chinese Super League running concurrently to the continental competition.
They are sending a side made up of largely reserve and youth team members. Not a single player is over the age of 22. The lowest squad number registered -- usually a good gauge of seniority and experience barring some exceptions -- is Yang Dejiang's No. 30.
But even Chen Guanxuan, the youngest member of the Guangzhou squad who only turned 16 in February, is likely to have more experience than Ratchaburi Mitr Phol's new signing Phakin Khamwilaisak, a Thai actor and singer who has somehow found his way to the ACL having initially joined the club's training sessions purely as a means to keep fit.
Yet, putting aside the unfamiliar and the unconventional, the AFC Champions League is still brimming with quality and will not fail to deliver as the top-level competition for Asia's best teams.
The earlier action in the West Zone has already proven that the expanded format has even more potential to produce drama and shocks, and the same can be expected in the East.
The 2021 AFC Champions League campaign has all the potential to be one of the best ever. It is just that it is already also likely to be one of the wackiest.