Twelve months on, Skelton and Waratahs coach Daryl Gibson both agree a stint in the UK with Saracens was worthwhile and has provided him with a new philosophy for the upcoming season; quality over quantity.

The problems started at the World Cup in 2015 when Skelton suffered a pectoral injury and subsequently required surgery.

He returned to NSW underdone after months on the sidelines, which gave Gibson no option but to drop him to the Shute Shield in March.

Skelton worked his way back for the Waratahs but when he joined the Wallabies, Michael Cheika said, of a player with "unlimited potential", that Skelton was not in the right condition.

The 24-year-old featured in four Tests last year before making the decision, supported by the Waratahs, to get more match fitness by playing with UK Premiership club Saracens.

Christmas and New Year was spent in chilly England but it was a move his coach says was crucial for Skelton to achieve his potential.

"He's come back a much better player for that experience and also in much better shape," Gibson said. "Will's had an excellent time at Saracens. Part of allowing him to stay on after the spring tour is firstly to get that experience with Saracens, currently the best team in Europe.

"He got himself to 140 kilos during the Wallabies campaign, went to Saries [Saracens] and kept training at their intensity, so he hasn't had much of a break. I expect him to pick up where he left off."

Skelton shares the same view, saying he is in excellent shape now.

"I feel a lot better," Skelton said. "The preparation I've had in the off-season has been a lot better than last year. I came off the back of an injury, tore my pec, so I was out for a while and I sort of got thrown [back] into it.

"Just coming off the back of the spring tour I played a few games there and then got the opportunity to play at the English club and it's good to get game time. I skipped the pre-season here but I'm more match fit and I'm ready to go against the Highlanders [in a trial on Thursday night].

"I wasn't in good form last year and I didn't warrant a spot in the [Wallabies] team so for me I've got to work on myself."

Those who coach Skelton discuss at length how best to use him. Some believe he needs to be fit enough to play 80 minutes, others think coming off the bench is a better use of his size and skill against a tiring opposition.

Skelton believes the best approach is to play 50 or 60 minutes of quality rugby rather than drift in and out of play across an entire match.

"Quality is the goal for me … if I can get through 60 or 50 [minutes] and go my hardest, empty the tank and really just build on that every game," Skelton said. "Playing a full game I reserve my energy until the last 20 or the last 10 [minutes] and I don't get the quality for my team, so that's the focus. I've spoken to Daryl about it, to really improve this year."

Known for his love of a big feed, Skelton cut back on the calories and improved his diet before the spring tour.

He says he gave himself a few "cheat" weeks in the UK but hoped he would reap the benefits when the Waratahs kick off their season against the Force before a two-week trip to South Africa to face the Lions and Sharks.

"I had Christmas and New Year's there, I fell off the bandwagon a bit over there but it's something that you've got to cherish as well, that time away from footy," Skelton said. "We had fun there but now it's back to work at the Tahs.

"Last year I was in and out of the Test squad and the Tahs so to keep that consistent place in the team, that's my goal this year."