Scarlets have confirmed Wales full-back Liam Williams has joined the region for the remainder of the 2019-20 season.
The region announced in December 2019 Williams would be returning from Saracens but he will link up with Scarlets sooner than expected.
"I would like to thank everyone involved for their support in making it happen," said Williams, 28.
Scarlets are waiting to see if Williams is released by Wales for the Pro14 trip to Munster on Saturday, 29 February.
Williams hasn't played since suffering an ankle injury at the World Cup in Japan in October 2019 and has been completing his rehab as part of Wayne Pivac's Wales Six Nations squad.
He is close to returning to full fitness and trained with the Wales squad before the defeat against France at the Principality Stadium.
Pivac has injury concerns over wing George North (head) and Josh Adams (ankle) after the pair were forced off against France.
Wales have two Six Nations matches remaining, with a trip to face England to Twickenham on 7 March before hosting Scotland seven days later.
Williams was initially due to return to Scarlets in the summer after three seasons in North London.
However, Scarlets, Williams and Saracens have since come to a mutual agreement that will allow the full-back to play for his former side earlier than initially anticipated.
English champions Saracens will be relegated from the Gallagher Premiership at the end of the season for persistent salary cap breaches.
Saracens had already been deducted 35 points and fined £5.4m for three seasons' spending above the cap.
'Happy Saracens memories'
"I've had a fantastic few years at Saracens and will take some very happy memories away with me," said Williams.
"I've been working hard on my recovery and can't wait to get back on the pitch."
Scarlets head coach Brad Mooar added: "Liam is a world-class player and man, a huge favourite at Parc y Scarlets and we are thrilled to welcome him back.
"To have Liam joining our exciting group of outside backs this season is superb. I'm also thrilled for Liam that his rehab is almost complete.
"His immediate availability for us will depend on how Wayne wants to play it during the Six Nations and we look forward to seeing Liam back at Parc y Scarlets in due course."
Scarlets general manager Jon Daniels revealed Williams will be available for the Pro14 and Challenge Cup competition with Toulon the quarter-final opponents.
"It's a great boost and we've worked hard to be in contention on both fronts," said Daniels.
"To be able to add someone of Liam's calibre to the existing group is great both on and off the field. It's different to get somebody mid season but you take them when you can get them.
"It will take Liam time to get up to speed because he's been away for a couple of years now and there's a different coaching group here.
"To be able to add somebody of world class quality we'll take that any time of the year regardless of when it is."