Scarlets powerhouse Parkes, 32, has 29 caps and would become ineligible for Wales if he chooses to move away.

He has been a key part of the Wales squad since making his debut in 2017, starting 11 of the last 12 matches.

Parkes is considering a bid from one of Japan's top-flight clubs, Panasonic Wild Knights.

Born in New Zealand, he was brought to Wales by then-Scarlets coach Pivac in 2014 at the age of 27 and made a successful debut against South Africa immediately after he became eligible on residency grounds.

"Hadleigh's coming off contract at the end of the season, he's got to factor in his age, a new family, where he's going to be living for the coming years, and the financial side," Pivac told BBC Sport Wales.

"Then he's got to weigh up playing Test match rugby, so it's not an easy decision. Hadleigh has a real passion for Wales and has enjoyed his time here but he also understands that fatherhood is part of his life, so a big decision for him."

Gloucester's Owen Williams, a centre or fly-half with three caps who was injured only minutes before his scheduled Six Nations return in Ireland in February, has also been linked with a possible Japan move.

But Saracens centre Nick Tompkins, who had a largely impressive first Six Nations, could be based with a Welsh region on loan for the 2020-21 season while his parent club is in the English Championship.

Pivac is confident about the Welsh Rugby Union policy of not picking players who have fewer than 60 caps if they choose to move away from the regions, or renew an existing contract outside Wales after their first selection.

He believes players appreciate the careful management of their schedules on home turf.

"I'm very confident, from talking to the players we used in the Six Nations about the pros and cons of playing outside [Wales]. Some guys picked up bumps when they went back [to English clubs] this season which took them out of selection," he explained.

"There are pros and cons. When you've played 60 matches plus, there can be financial implications, you can make more by going outside Wales potentially, but you've got to balance it up with longevity in the game.

"There are a lot of players selected for the first time that understand that playing in Wales is going to be beneficial to their Test careers going forward."