Warriors centre Konrad Hurrell is in doubt for Sunday's clash against the Manly Sea Eagles after suffering a head knock during Saturday night's 28-22 loss to the Brisbane Broncos.
Hurrell was yesterday named in coach Andrew McFadden's side to face the competition leaders but sat out team training and was due to undergo further concussion tests.
"He's going to get tested this afternoon and we'll just see how he goes," McFadden explained. "We kept him out of training today based on the recommendation of our doctor. He's going okay. We're optimistic that he'll be fine because he's not having a lot of symptoms."
Back-rower Feleti Mateo withdrew from the session with a calf concern, but McFadden said his departure was precautionary while the extent of the problem was yet to be determined.
"His calf just tightened up towards the end of the session. As we did last week with Sam [Tomkins], as soon as they tighten up we just take them off the field and get them assessed.
We'll just have to wait and see what the medical staff comes back with."
McFadden has made two changes, recalling Ngani Laumape to the right wing after a three-game suspension, and prop Sam Rapira joins an extended bench. Laumape comes in for 19-year-old David Fusitu'a while Rapira, who missed the last two matches with a back problem, comes on to a five-man interchange for Agnatius Paasi. He joins Mateo, Ben Matulino, Thomas Leuluai and Jayson Bukuya, who was 18th man last week.
"There were aspects of our performance which were disappointing last weekend. In the first half much of the detail which has been good for us wasn't at the level we expect," McFadden said. "A few areas we've been priding ourselves on weren't quite as good so I've made some changes based on that."
The Sea Eagles, beaten grand finalists last year, took outright ownership of the competition lead on 28 points with Monday night's 21-12 win over St George Illawarra.
McFadden acknowledged Sunday's match-up looms as the Warriors biggest test since he took charge of the side in round six.
"It's certainly a great test to see where we are. They're obviously on top of the table at the moment and they've got strike right across the park.
"They're a very physical, aggressive type of team, so this is a team that we need to beat if we want to compete with the big guys at the end of the season."
McFadden brushed off talk the visitors could arrive here a divided outfit, after reports out of Sydney claimed three of their big stars - Steve Matai, Brett Stewart and Anthony Watmough - were seeking releases.
"They're still performing on the field. It's certainly not impacting their performances. I think it's all a bit of a beat-up. They're probably a very happy club and that's what they'reall saying and from what I hear,it is."