Warriors centre Konrad Hurrell is undergoing further concussion testing to determine whether he will be fit to face competition leaders Manly at Mount Smart on Sunday.

The bruising ball carrier did not return from a head knock as the Warriors fell to the Broncos in Brisbane last weekend and was absent from training on Tuesday, pending tests during the afternoon, along with four other starters.

“We kept him out of training based on the recommendation of our doctors,” said coach Andrew McFadden.

Manu Vatuvei and Ben Henry, who are both dealing with ongoing knee problems, were also absent along with Dane Nielsen and Sebastine Ikahihifo.

Meanwhile, McFadden has made just one change to his starting lineup with Ngani Laumape returning from suspension to the right wing at the expense of David Fusitu’a.

Veteran prop Sam Rapira has also been named on an extended bench after recovering from a back injury.

McFadden said the squad were “brutally honest” during the review of their 28-22 loss at Suncorp Stadium, during which they surrendered the lead twice due to simple errors.

After watching Manly take the outright lead on the NRL ladder with a 21-12 win over the Dragons at WIN Stadium on Monday night, McFadden said this week’s clash would be the ultimate test of their Premiership credentials.

“It’s going to be a great test to see where we are. They’re obviously on the top of the table at the moment and it’s going to be a big challenge,” he said.

“They’ve got strike right across the park. They’re a very physical and aggressive type of team. So this is the team that we need to beat if we want to compete with the big guys at the end of the season.”

The Warriors have won just one of their last eight encounters against Manly, and McFadden identified fullback Brett Stewart as a major threat.

The former New South Wales and Kangaroos representative is the all-time try scoring leader in head-to-head clashes between the clubs and has scored six so far this season.

“He’s the key to their whole attack. Most of the quality stuff that happens around the ball revolves around him and he’s a very good player,” McFadden added.

Last time the two sides met at Mount Smart, in June last year, the Warriors won a thriller 18-16, ending a run of six straight losses.

Warriors: Sam Tomkins, Ngani Laumape, Konrad Hurrell, Dane Nielsen, Manu Vatuvei, Chad Townsend, Shaun Johnson, Jacob Lillyman, Nathan Friend, Suaia Mataki, Ben Henry, Simon Mannering (captain), Sebastine Ikahihifo. Interchange: Feleti Mateo, Ben Matulino, Jayson Bukuya, Thomas Leuluai, Sam Rapira.