He played at the 2007 Under-13 Craven Week in Krugersdorp,[2] kicking fourteen points in four appearances to finish as Limpopo's third top scorer in the tournament.
The Under-19 team finished top of the log with 12 wins out of 12 to qualify for the play-offs,[12] and Marais kicked 17 points to help his side to a 37–21 victory over Leopards U19 in the semi-final.
[14] Marais' total contribution of 126 points ensured he was the top scorer in Group A of the competition, despite missing several matches due to playing at Under-21 level.
After making two appearances as a replacement in 2013, Marais made his first start in senior rugby in their opening match against the Falcons, kicking 12 points in a 37–13 victory.
Marais scored his side's only point in a low-scoring affair, which the team from Cape Town won 10–6 to eliminate the Blue Bulls.
[30] He started their opening match in the competition, a 10–28 home defeat to Boland Cavaliers, to make his Currie Cup debut and scoring the Kings' first points of the season, via a 36th-minute penalty.
[33] However, Pieter-Steyn de Wet established himself as the Kings' first-choice fly-half for the remainder of the competition, and Marais made just one more appearance as a replacement in a 25–57 defeat to the Free State Cheetahs.