"I'm very excited to join Surrey and I have some fantastic memories from playing at the Kia Oval last year," Johnson said. "Surrey have a great squad and I can't wait to contribute with the ball in front of the packed out crowds in south London."

Alec Stewart, Surrey's director of men's cricket, said: "Spencer is a highly talented cricketer who has shown his skills in white-ball cricket at the highest levels. He will add strength to our bowling unit in the first part of the group stages when we have four players away at the World Cup with England."

Following the T20 Blast, he will turn out for LA Knight Riders in Major League Cricket, before returning to The Oval for his Hundred stint with Invincibles. He could also add to his six international caps at the end of the English summer when Australia tour for three T20Is and five ODIs. Johnson is not centrally contracted to Cricket Australia, meaning the board has no say over his domestic commitments.