Cowboys lock Jason Taumalolo is in doubt for New Zealand's Test series against England.

Cowboys fit for title defence

Cowboys coach Paul Green is notoriously a hard man to please, but the energy, intensity and fitness displayed by his squad earlier this week almost brought a tear to his eye.

The introduction of new interchange rules and a 'shot clock' has forced a rethink of all 16 club's pre-season fitness regimes, with increasing front-rowers' aerobic capacity at the forefront of thinking.

Burst players like lock forward Jason Taumalolo, hooker Jake Granville and utility forward John Asiata will be keenly impacted by increased playing time, and Green says they have already made huge strides in the pre-season.

"I'm really happy with where we're at. I was a little bit nervous given the time we had; there was only three weeks before Christmas and after Christmas," Green said.

"That was a concern for me, but our players came back in really good condition and it allowed us to hit the ground running. Where we are physically, I'm pretty happy with that.

"They're a pretty tough group mentally. It's been a bit of a challenge to manage all of (the pre-season commitments) and to make sure that we get them right and get them physically feeling up for Saturday night."

As the players admit, much of the credit for the impressive fitness levels goes to their improved High Performance Unit.

Borne out of the Cowboys' inability to perform consistently, particularly on the road, the performance department received increased attention and resources from the club prior to last season, and it again appears to have paid dividends ahead of the 2016 campaign.

Taumalolo admits that while running is generally not a passion of middle-field players, the HPU has kept morale high in the face of a more taxing workload.

"As the middle guys we've done a lot more running this pre-season than anything else; just trying to make sure the body can cope with the big minutes if they're needed to," Taumalolo said.

"They have reduced our weightlifting so we can do more running, and I think the boys are happy enough with that. It will be a good test for us this whole year as a middle unit.

"[The faster game] will mostly affect us boys in the middle, but I'm still pretty confident the club will work on a good rotation that will help us out with the new rules. If it requires a few of us boys to play a few more minutes we will be more than happy to put our hands up.

"The club is more wanting quality than quantity with me, so it will be interesting to see how I play it out on Saturday."

Every year there are question marks over the desire of teams fresh off a premiership – considering that no team has won back-to-back titles in a unified competition since Brisbane in 1992-93 – but early indications are that Green has his men firing on all cylinders ahead of opening night.