The Tehran-based side were on a high after an impressive comeback win over Al Duhail in the quarter-finals but were dealt a blow when vice-captain Hossein Mahini suffered a long-term cruciate ligament injury in a league game.

Mahini will be joined by fellow defender Mohammad Ansari on the sidelines, after the latter received an automatic suspension for the first leg. Despite the setback, Nourollahi stressed that his side was prepared to lock horns with Al Sadd.

This is the third IR Iran-Qatar match-up in the 2018 AFC Champions League knockout stages. The quarter-finals saw Al Sadd defeat Esteghlal 5-3 on aggregate, while Persepolis mounted a thrilling comeback in the second leg to eliminate the previously rampant Al Duhail side.

The former Atletico Madrid captain signed for Al Sadd in the summer and made his AFC Champions League debut in the quarter-final clash with Esteghlal. After a 3-1 win in the first leg in Tehran, the Qatari side held off Esteghlal's challenge and drew 2-2 in Doha to secure a spot in the semi-finals.

Gabi played a key role in the win over Esteghlal and is now looking ahead of taking on another Iranian giant, Persepolis, in the last four. Speaking ahead of the first leg of the semi-final in Doha, the Spanish midfielder emphasised his team's readiness.

Leading scorer Baghdad Bounedjah and Spanish superstar Xavi may have hogged the headlines as Al Sadd reached the AFC Champions League semi-finals, but it is young Qatari talent Akram Afif who has been one of the real success stories of the Doha club's continental campaign.

And according to the 21-year-old forward, who was recently named AFC Champions League Toyota Player of the Week, the best is very much still to come.

For the first time since the introduction of the East v West final in 2013, all four teams in the West Asian quarter-finals come from just two countries, offering us the opportunity to watch two tasty IR Iran v Qatar encounters, as Tehran giants Estaghlal and Persepolis face Al Sadd and Al Duhail respectively.

Throughout the years, teams from the two nations have produced some classics when they met. Here are four memorable matches between them from recent editions of the competition.

The J.League side are appearing in the last four for the first time after finally advancing from a knockout round match for the first time, while two-time continental champions Suwon last played in the semi-finals back in 2011.

The pair met twice in the group stage, sharing a win apiece, with Kashima claiming victory in Suwon and Suwon gaining revenge in the final round of fixtures to top Group H at the last.

34 goals down, two more to go. Legendary forward Damjanovic's love-affair with Asia's premier club competition keeps enduring.

A runner-up in 2013 with FC Seoul and again a semi-finalist in 2016 with the capital city club, the prolific Montenegrin is now back in the business end of the tournament with Suwon.

Just a brace off the record of current AFC Champions League all-time top scorer Lee Dong-gook, whose side Jeonbuk Hyundai Motors were eliminated by Suwon in the quarter-finals, Damjanovic has one eye on that record but - naturally - both on lifting the title itself.