Cape Town - The Springboks' quarter-final opponents at the Rugby World Cup will determine what scrumhalves make the match-day squad, coach Rassie Erasmus has hinted.

Erasmus addressed reporters in Kobe on Tuesday after his side booked their spot in the quarter-finals with a 66-7 win over Canada.

Cobus Reinach, considered the third-choice scrumhalf behind Herschel Jantjies and Faf de Klerk, was the star of the show after scoring the fastest hat-trick in World Cup history.

Reinach's hat-trick inside 20 minutes beat Australia fullback Chris Latham's feat after 25 minutes in a 142-0 thrashing of Namibia during the 2003 World Cup.

And Reinach's performance may have prompted Erasmus to rethink his scrumhalf picks in the knockout phases.

"We're privileged to have three scrumhalves like Cobus, Faf and Herschel. We've done well to spread out the workload between then (during the pool games)," Erasmus said, as quoted by Netwerk24.

The Boks will face either Japan, Ireland or Scotland in the quarter-finals and this could have an impact on which scrumhalves crack the nod in the match-day squad.

"We'll analyse the game against Canada and look at individual things. We'll also have to look at who we'll be playing. It will have an influence on our choices," Erasmus said, noting that Japan, Ireland and Scotland all have different playing styles.

Erasmus also heaped praise on Reinach for his efforts against Canada.

"Everybody knows he has the X-factor - I knew his dad (the late former Springbok wing Jaco Reinach) well," said Erasmus.

"He's got exceptional speed, he hasn't had a lot of game time with us since I've been coach, but he's got good speed and anticipation."

- Compiled by Herman Mostert