Selection involves many variables. Trends and traits change with seasons and selectors but Shields has now drawn a line through his childhood dream of representing the All Blacks.
Before departing for Wasps, and chasing a spot in Eddie Jones' English side, one he qualifies for through his parents, Shields appears determined to lead the Hurricanes to glory.
"It was the hardest decision of my life so far but I've just got to back myself," Shields tells the Herald on Sunday. "I'm lucky to get another season with these boys and finish with Wellington on a high. I'm stoked with the team we've got this year and how hard we're working. The goal is to win a Super Rugby championship so that doesn't change at all."
There was a sense of irony as Shields went head-to-head with Kaino in the final preseason hitout in Warkworth on Thursday. Kaino's commanding presence is one of the main reasons Shields' path to the All Blacks has been blocked. Now, they are both preparing to move offshore after this season.
No matter what level they sit, every rugby player wants to take the next step. Now 26 and in a brutally combative position, Shields felt the turning point in his career had arrived. No longer was he prepared to stay and wait for the possibility of replacing Squire or Hurricanes team-mate Fifita.
Pushing aside the pedestal wasn't easy, though.
"For a player growing up your goal is to play for the All Blacks. It was a hard decision to try and not go for that anymore. I'm pretty stoked with the way I've gone and the way I've played. One more Super title and I'll be happy. I've left no stone unturned and gave it my very best. There's another opportunity that's opened up so I've got to grab that.
"Damned if you do damned if you don't so that's the way it is. I'm pretty pumped about where I'm heading and excited for the future."
Kaino's knee injury on last year's northern tour was thought to have seen Shields tapped on the shoulder for a long-awaited All Blacks call-up. Shields, however, says he was unavailable.
"My daughter was due at that time of year so I made the decision to take myself out of that area and be there for my wife. I would've loved to play for the Baabaas again but it didn't quite work out. Family comes first sometimes. But I was pretty set before then that I was going to be heading away."
You get the sense the next six months is personal for Shields. He has pushed any thoughts of wearing the Red Rose out of his mind and is instead intent on righting the wrongs from last year when the Hurricanes blew a 22-3 lead to lose their semifinal 44-29 in Johannesburg.
"We were in the driver's seat for a lot of the season and it was down to our own fate. The lesson would be to win more games and get a home semi. We let ourselves down. We know we could have played a lot better so maybe our focus needs to be better for 80 minutes rather than switching on and off. It was a tough pill to swallow but hopefully we can come out on top this year."
Aside from Shields' drive to signoff with a title, there is also the undercurrent of Hurricanes coach Chris Boyd moving north after this season too.
"He's in the same boat as me. He's put a lot of time into this jersey so hopefully we can do him justice."
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