Back-up hooker Joel Luani says it's time for the Wests Tigers to show they can win without talismanic skipper Robbie Farah, and he's going to use his full attacking repertoire to do it. 

The Tigers have lost four of their five games without captain Robbie Farah this season, suffering defeats to the Gold Coast, the Roosters, Brisbane and South Sydney earlier in the year. 

Their disappointing record has led to coach Mick Potter calling on his back-up rake to make his mark on the team – and the NRL. 

"I'm trying to improve every time and right now I need to take more ownership instead of giving service to Brooksy [Luke Brooks] and Braith [Anasta] at the same time. It's time to step up and put my stamp on," Luani said on Thursday. 

The 22-year-old lines up for just his ninth first-grade game when they host Penrith at Leichhardt Oval on Sunday, and he admitted struggling to adapt his game to NRL-speed. 

"When you start out, you tend to think, 'Just don't make any mistakes' when you come up," he said. 

"But now it's time to take ownership and start exploiting the defence when I can and not so much give service, but also hopefully take some half-opportunities for myself."

Luani said a deep review alongside Potter of his five games this year has revealed the American international needed to put more pressure on opposition defences.

"I just think I've been struggling to bring it to the NRL. Mick's been happy with how I've been going. I've always known that there's room for improvement and so does Mick," he said. 

"It's been pretty clear that I'm a defence-first hooker and I enjoy defending. In attack, [I need to] just look to bring in a bit more of my running game and subtlety and things like that.

"Doing the review with each other, we just know there are little cracks where I can take opportunities and not be afraid of them. I can't just shy away because I'm in the NRL. I've had a few games now and it's time to step up."

Halfback Luke Brooks also said he too needed to elevate his game in the absence of his skipper and that a win against Penrith would give the team plenty of confidence as they head into the final third of the regular season. 

"Definitely, it'd be a massive confidence booster for the boys if we can get a win without Robbie and Woodsy in the team because the last few games without them we haven't played our best," Brooks said. 

"Hopefully we can turn that around this week and play a good game without them two... because when [Farah] is playing, he controls the game well. I guess I've just got to take more ownership of the team and be more dominant without him."