Wales lock Jake Ball will quit international rugby to be with his family in Australia at the end of the season.
His wife, Christie, gave birth to their fourth child in Australia in November.
Ball, 29, has won 49 Wales caps since his 2014 debut and impressed as one of the leading forwards during the autumn.
“It has been a difficult decision to make but one I have made for the family,” said Ball.
“Max was born last month. There have been Zoom calls and things, but I haven’t seen him yet and it has been difficult.
“I have four kids now and I won’t have seen them for close on a year.”
Wales coach Wayne Pivac must now consider his lock options beyond 2020-21.
Under current rules, players must pass the 60-cap mark to be eligible to play for Wales if they sign for teams outside the country.
Ball was born in Ascot, Berkshire with a Welsh father and the family later moved to Australia, where he shone at cricket and trained with Western Force rugby team before joining Scarlets in 2012.
Ball said: “My wife was expecting our fourth child and, with Covid around and players having to be in bubbles and everything, we made the decision that she and the kids should go home to have some family help and support around her.
“As the season goes on, it would be pretty tough of me to ask Christie to come back here away from her family again.
“It has been a fantastic nine seasons I have been here. I love the Scarlets and playing with Wales has been unbelievable and something I will never forget.
“It has been a massive honour to represent my country, but at the end of the day I made a huge sacrifice in staying behind for a year without my family.”
Ball added: “I was at the Western Force before, but it was the Scarlets who gave me my first real shot in senior rugby and it will be nice to finish off on a high and reward the Scarlets for everything they have done for me over the years.
“I have some very special memories and have got to do some fantastic things. We have won the Pro12, made a European semi-final; there has been a Grand Slam and two World Cups with Wales. I have no regrets with what I have done here.
“I am just hoping we can have supporters back at Parc y Scarlets before the end of the season. It would be great to have them here so I can say my farewells properly.”
Head coach Glenn Delaney said Scarlets “fully respect” Ball’s decision.
“Family is a massive part of the Scarlets and Jake has sacrificed a huge amount being away from Christie and his children for so long,” said Delaney.
“He has been a wonderful servant for the Scarlets, an outstanding player, a great bloke around the group and has been a fantastic mentor to the young players who are coming through.
“You saw by his performance against the Ospreys on Boxing Day what playing for the Scarlets means to him.”