Todd Carney says studying Johnathan Thurston's play on video helps him with his own game as a five-eighth.

There’s no greater challenge in the NRL than coming up against Cowboys five-eighth Johnathan Thurston, according to Cronulla playmaker Todd Carney who rates ‘JT’ as simply “the best”.

On Sunday Thurston and Carney go head to head in a crucial match-up that will have a huge influence on their teams’ finishing positions – and the make-up of the 2013 finals series.

And for Carney, with the playoffs just a fortnight away, there’s no better way to tune up than coming face to face with Thurston.

“For me personally it’s always a big test playing against someone like Johnathan Thurston. That’s what I always think about first when we play the Cowboys,” Carney tells NRL.com ahead of the Sharks’ clash with North Queensland at Remondis Stadium.

“He’s the best. It’s pretty simple. When he’s ‘on’ he’s the best. He’s their main indicator. I watch him most weeks on video – when the Cowboys play you always want to watch.”

Carney, in fine form for Cronulla across the entire 2013 season and one of the favourites to win the Dally M medal, says when he watches Thurston play he’s both mesmerised and, through breaking down JT’s play, tutored too.

“I do a bit of both [analysing his play and simply watching it],” Carney says of watching the Queensland and Australian legend. “You obviously don’t do what other players do because you’ve all got your own style but you try to simulate a few things but yeah I just like watching the things he does.

“He plays off the top of his head, he’s smart… you can always take things out of his game.”

The Thurston-led Cowboys are one of the NRL’s hottest sides at the moment, on the back of four consecutive victories, and Carney is expecting a well-drilled and highly dangerous outfit when they arrive at Remondis on Sunday.

North Queensland have everything to play for, too – they currently sit in eighth position and need a victory to stay ahead of a pack of four other teams also on 24 points. They’ll have to do it without the services of half-turned-hooker Ray Thompson too, who sustained a broken jaw in last week’s win against the Knights.

“They’re playing really good football now and they’re desperate to be in the top eight – it’s going to be a great challenge,” Carney says.

“They’re class, they’re finding form. If you look back to the start of the year they were being picked by experts to be in the top four – and so they should be. Now they’re finding form and starting to prove to people why they’re regarded as one of the better teams.

“Their forwards are great and their backs are great. I think it’ll be a big loss losing Thompson though – he’s been really good for them around the rucks.”

The Sharks, meanwhile, are assured of a top-eighth finish but would like a victory to maintain the momentum as well as keep their slim top-four chances alive. Cronulla, also in fine form, have won four of their past five matches – including a last-start upset over the table-topping Roosters on Monday night.

Carney has been integral to their regular-season success, but he is the man most pivotal to their post-season progress – and he knows it, too.

“For me I’m just happy with how my form’s been. I don’t really look too much at myself. When we win I like it to always be a team performance,” Carney says.

“I’m just happy with where I’m at. I had a limited pre-season with an Achilles injury and it’s really good at the moment.

“Things I’m practising at training are coming off in the games and for me I just want to keep getting better and I want to perform in the semi-finals when we get there but as we’ve spoken about, I’ve got a big job on Sunday in our last home game of the season. I’m going to put all I’ve got into that this week.”

The Cowboys are on guard for a Shark attack – and a loss could well end their season. Outgoing coach Neil Henry is expecting a huge challenge from the Shire boys.

“They’ve been very good at home and very good all year,” Henry says. “They’re entrenched in the top eight and have welcomed back (Paul) Gallen and (Luke) Lewis [from injury] and Carney’s going well, too. It’s certainly a tough game.”