Tandy has fielded five different midfield partnerships so far, and could add to that tally after Owen’s call-up.
Ben Thomas started against South Africa in July but misses out because of a calf injury, with the uncapped Dragons centre now pushing for a chance at 12.
Owen, a member of the Wales squad in the summer 2021 after a breakthrough season when he broke up the expected partnership of Jamie Roberts and Nick Tompkins, has been rewarded for club excellence.
“He has been outstandingly consistent and does everything really well. Speak to coaches and they mention his standards on and off the field, how he is the last one off after working on extras,” Tandy told Scrum V.
“He has had injuries, and you could argue he could have been in the selection mix sooner, but what I love is that he has kept going and kept getting better.
“He has been so consistent and at a high level, not just seven out of 10 but above that.”
Owen is a specialist 12 to rival Joe Hawkins, who is with Scarlets in South Africa to play Stormers this weekend along with Taine Plumtree.
Eddie James is one of the five Wales squad members to stay at home, with Tandy likely to field him in the Nations Championship opener against Japan.
There has been debate about the powerful back’s best position – with many feeling he has the bulk for inside centre, where he started Scarlets’ first two games of the season – but Tandy is sticking to his guns.
“I see Eddie more as a 13. He can definitely play 12, as we have seen for the Scarlets, but in our team he is more of a 13 who can play 12,” he said.
“Louie Hennessey, Max Llewellyn and Eddie, they have big frames and there is lot of interchangeability for the 12s and 13s. We have a nice variety of options there.”
Tandy has made his first selection of the Nations Championship, but there is plenty more scrutiny ahead with four team announcements to come.