The two countries will be meeting for the first time
Morocco will play Iran for the first time in a World Cup as they start their Group B campaigns on Friday afternoon (4pm BST).
Morocco and Iran boast strong defensive records heading into their opening game at the Krestovsky Stadium in Saint Petersburg.
Morocco were the only team not to concede a single goal in the third round of African qualifying, while Iran kept nine straight clean sheets in AFC qualification, letting in just two during their final game against Syria.
Iran striker Alireza Jahanbakhsh finished as last season's Eredivisie top scorer with 21 goals for AZ Alkmaar.
Morocco playmaker Hakim Ziyech - who plays his club football for Ajax - contributed the most assists in the Dutch league with 21.
Former Manchester United assistant Carlos Queiroz and ex-Cambridge United boss Herve Renard will look to navigate their respective nations out of a tricky group which includes Portugal and Spain.
Team news
Iran will be without the suspended Saeid Ezatolahi, while there are fitness doubts surrounding Mehdi Taremi and Askhan Dejagah.
Morocco will be hoping Nabil Dirar is passed fit. Dirar missed Morocco's last two friendlies against Slovakia and Estonia due to a calf injury.
Opta stats
Morocco and Iran have never met at the World Cup.
They've faced each other only once previously, a game which ended in a draw.
Morocco have qualified for their fifth World Cup, their first since 1998.
They have never progressed further than the round of 16 (1986), being eliminated in the group stages three times in their four previous appearances.
Iran have qualified for the World Cup in back-to-back tournaments for the first time.
However, they have never reached the knockout stages, winning only one of their 12 games (D3 L8) - against USA on 21 June 1998 (2-1).
Carlos Queiroz is taking part in his third consecutive World Cup tournament as manager, and second in a row with Iran.
His best performance was in 2010, when he led Portugal to the Round of 16 before being knocked out by eventual winners Spain.
