Sarries bolster scrumhalf stocks
Stirzaker will be with the club until March.
London-born Stirzaker was raised in Australia from the age of two and has played a crucial role for the Rebels since starting his career with the Super Rugby side in 2012.
The 26-year-old captained the Melbourne Rising team to victory in the inaugural National Rugby Championship in 2014 and enjoyed a breakout 2015 season, scoring his first Super Rugby tries and becoming a stalwart in the Rebels team.
He was made captain of the Melbourne Rebels Super-Rugby outfit in 2016 and became the youngest Rebels player to reach 50 appearances last year.
Stirzaker has represented the Barbarians, playing for the invitational side in November – before joining up with Saracens at the end of the year.
He arrived at Saracens as the team prepares to take on a busy schedule, starting with a trip to Coventry to face Wasps followed by a crucial double-bill in the European Champions Cup with games against Ospreys and Northampton Saints.
"I've settled in really well, St Albans is a cool place; the club's been really great and it's a cool bunch of guys. The last couple of games have been two good wins so it's a good place to be around," Stirzaker said.
"I'm looking forward to learning from some really quality players here as well as learning from the way the team plays; the game is based around a kick-chase and accurate kicking which is something I'm really keen to develop."
Director of Rugby Mark McCall said: "Nick's an experienced player, he's got 60 Super Rugby caps which is a lot for a young man.
"He's a very exciting scrum-half with great passing ability, great running ability and with Henry Taylor out for the rest of the season and with Richard Wigglesworth's recent injury we fell a little bit vulnerable in that area, so it's great to be able to bring Nick's quality across."
