Srecko Katanec expects a "big challenge" when Iraq take on Qatar in the last 16 of the Asian Cup, but has warned his side's opponents that their impressive group record will count for little.

Qatar advanced through to the knockout rounds with a perfect return in Group E, overcoming Lebanon, North Korea and Saudi Arabia.

Felix Sanchez's side scored 10 goals and did not concede once, allowing their opponents just three shots on target overall in their three matches - fewer than any other side.

Iraq finished second in their group, meanwhile, taking six points from six against Vietnam and Yemen before being held 0-0 by Iran, who claimed top spot to set up a clash with China.

Having seen Jordan, another side boasting a perfect defensive record after three games, get knocked out by Vietnam on penalties, however, Iraq head coach Katanec says nothing is certain.

"Our form is good but we must be on our toes against Qatar," he said at a media conference. "Jordan went into their match against Vietnam having not conceded one goal but the first one they did was enough to eliminate them from the tournament.

"Qatar will be huge challenge as they are very adept in changing tactics and formations. My message to the players is that we must be quick to adjust to Qatar.

"We have been taking it one match at a time and I have not pressured the players by saying we must win. The players, however, are determined to give their countrymen joy and we will give our best against Qatar."

Katanec has been in charge of Iraq for just five months, compared to 18 months at the helm for opposite number Sanchez.

This marks just the third time Qatar have progressed from the group stage, suffering elimination in the first knockout round on the two previous occasions, losing to China in 2000 and Japan in 2011.

Former Barcelona youth coach Sanchez, who has worked his way through the Qatari ranks to his current position as senior team boss, acknowledges the importance of remaining focused for this next big challenge to avoid the same fate as Jordan.

"This is the knockout stage and it all boils down to one match. One defeat and we go home," he said at a media conference.

"We too didn't concede a goal in the group stage but all that can change in an instance and we could be eliminated. This is something that we don't want to happen and the players know that there must be full concentration."

PLAYERS TO WATCH

Qatar - Almoez Ali 

As well as boasting a perfect clean sheet record in the group phase, Qatar also scored an unrivalled 10 goals. Ali was responsible for seven of those, four of which came in the 6-0 thrashing of North Korea - only Iran's Ali Daei has scored more in a single finals tournament, with eight in 1996.

Iraq -  Mohanad Ali

If Iraq are to make it through to the quarter-finals, they will likely have to breach their opponents' net. Plenty of focus will therefore be on striker Mohanad Ali - the youngest player at the Asian Cup - who scored in the wins over Yemen and Vietnam.  

KEY OPTA FACTS

- Qatar finished top of the group stage in the Asian Cup for the first time – in their previous two advancements to the knockout stages, they have lost at the first attempt: vs China in 2000 and vs Japan in 2011.
- Qatar allowed their opponents just three shots on target overall in their three group stage matches at the 2019 Asian Cup; fewer than any other side.
- Iraq haven't won an Asian Cup knockout stage game since winning the competition in 2007 (D1 L3), although they did win on penalties in the quarter-finals of the 2015 edition after drawing in normal time with Iran.
- Qatar's Akram Hassan Afif created the most goalscoring chances at the 2019 AFC Asian Cup in the group stages (10) and also assisted four goals, which no player managed more than.