Capped for both the Wallabies and Samoa, the 37-year-old started his career with the Brumbies back in 2008, amassing 150 appearances over 11 seasons.
Playing for seven outfits across Australia, Ireland, Japan and New Zealand, Lealiifano most recently turned out for Auckland in the NPC this year.
But without a contract with Super Rugby club Moana Pasifika, he jumped at the chance to play with RFCLA in the United States, where the men's Rugby World Cup will be played in 2031.
The LA club has Australian ties with former Wallabies Stephen Hoiles (director of rugby) and Dave Dennis (senior assistant coach) holding roles.
They have recently signed former Shute Shield-winning captain and Randwick backrower Ben Houston, as well as promising Melbourne Storm speedster Robert Mapa.
Lealiifano, who overcame leukaemia in 2016-17, told AAP he didn't feel ready to call time.
"I had a little stint in the NPC and I was still feeling really good and I didn't know what was next so I was looking to move back to Canberra," the five-eighth said.
"And then Hoilsey rang and said that they were looking for a 10 and I was stoked.
"Globally, you see people like LeBron (aged 39) and Tom Brady (retired at 44), and even Ronaldo, (Lionel) Messi, those types of guys playing on.
"Obviously they're way bigger but with the way sport science is going and recovery, if you look after your body you want to squeeze as much out of it as you can.
"It's inspiring to see them all keep playing ... there's no reason why not."
He said he had been impressed by the standard of Major League Rugby and wanted to help the code improve its profile leading into the World Cup.
"I've always wanted to help develop other players around me," he said.
"If we can grow the game over there to help, obviously, their national side as well, and then have a really good World Cup tournament.
"Obviously, the Americans love their sports so it's about trying to make them love rugby as well."
Signing a one-year deal, Lealiifano will be joined by his wife Luga and eight-year-old son Jeremih.
"This was probably the first time she's asked, 'how much longer' but she's always been really supportive," he said.
"The sacrifices they make for me helps motivate me and drives me to be successful wherever I go."
Hoiles said Lealiifano's recruitment would be a boon for more than just the team at RFCLA."Christian has achieved so much in his career and he still wants to keep playing and be as good as he can," he said."He's a really key signing, not only for us but also a recruit that will benefit the whole competition."
35°C