Having previously represented South Africa at the 2016 Summer Olympics, Mothiba broke into the senior side in 2018 after which he became the first player to score in three consecutive matches for the nation from debut.

He never progressed to the club's first team, however, and later joined Diambars academy in South Africa from whence he was signed by French side, Lille in 2014, shortly after his nineteenth birthday.

[9] With Lille battling against the prospect of relegation, Mothiba returned to score five goals in 14 appearances, including a brace against Dijon on the final day of the season, to ensure that the club avoided the drop to Ligue 2.

[12] On 30 March, he started in Strasbourg's penalty shoot-out win over Guingamp to help the club lift the Coupe de la Ligue title.

[13] On 9 November 2019, on the occasion of his 50th appearance for Strasbourg, Mothiba ended a five-month goal drought with a brace in the club's 4–1 league win over Nîmes Olympique.