All teams across the four groups are still in contention for qualification to the Round of 16, setting up some tasty encounters in the eight matches taking place across Monday and Tuesday.

A 1-0 defeat to Al Hilal a fortnight ago left the Tehran-based side in third place with four points, three adrift of their Monday opponents and five behind leaders Al Hilal.

Esteghlal’s woes were compounded when a 1-0 loss to Padideh in the Iranian Pro League, resulting in the suspension of the services of coach Winfried Schafer, with assistant Farhad Majidi taking over at the helm.

The reigning Saudi Pro League Champions sit top of Group C with nine points, two points ahead of their nearest chasers Al Duhail. They welcome to Riyadh an Al Ain side who are yet to record a win this campaign and are bottom of the group with two points.

The two weeks since their last AFC Champions League outing saw drastic changes at Al Hilal. The club parted ways with head coach Zoran Mamic and the former Al Ain man was replaced by Pericles Chamusca until the end of the season.

The hosts are third in the group with five points, one point ahead of their opponents. The two sides are still in the thick of the battle for knock-out stage places, with the other two Group D sides only marginally ahead of them.

Both teams fell to 2-1 away defeats on the previous matchday; Persepolis losing to Al Ahli in Jeddah, while Pakhtakor were beaten by Al Sadd in Doha, leaving the Qatari side top of the group with seven points and Al Ahli second with six.

The Matchday Five fixture is the fourth encounter between the two sides in the past 12 months. A brace from Boualem Khoukhi gave Al Sadd a 2-1 win at tomorrow’s venue in the first leg of the 2018 AFC Champions League Round of 16. The Qataris sealed qualification with a 2-2 draw in Jeddah a week later.

Al Ahli’s 2019 campaign started where they left off the previous year, but this time they were able to overcome Al Sadd 2-0 thanks to an Omar Al Somah double.

AFC Champions League winners in 2017, Urawa were bitterly disappointed to miss out on the chance to retain their crown in 2018 after failing to qualify for the tournament.

So, for many at the club, the 2019 edition has acted like a title defence for the Saitama side. And yet it has not gone quite to plan.

A tough Group G sees them third with just four points going into Matchday Five, and Australia international Nabbout insists that nothing less than victory in Buriram will do.

Korea Republic's Ulsan knows what it takes to win the AFC Champions League and, moreover, they know what it takes to do so unbeaten having done just that in the 2012 edition.

While it is far too early to say, the 2019 version of the team is set to replicate this, they have certainly begun in similar fashion having not lost in their first four fixtures, and are one of just three sides yet to taste defeat.

The-AFC.com spoke exclusively to Ulsan's Norway-born United States international Diskerud to get his views on the tournament so far, how deep the Korean club can go, and what lies in store for Tuesday's tie with Sydney FC.