The return of Springboks captain Siya Kolisi, who was sidelined with an injury, ahead of the Rugby World Cup is "massive" for South Africa, according to wing Cheslin Kolbe, who also believes the squad has more depth than it did when it lifted the trophy in Japan four years ago.

Kolisi suffered a serious knee injury in April, casting major doubt over his availability for the team's title defense, but has been selected for the first time this year for Saturday's warm-up game against Wales in Cardiff.

"It's massive for us as a team to have Siya back in the mix," Kolbe told reporters on Wednesday.