The 21-year-old, who joined The Athenians on loan from Lille in January, scored in his third outing for the club in a 2-0 win over Troyes on Friday.
"It's the greatest thing ever scoring your first goal in France. I have only played like a few games because I just came back from an injury," Mothiba tells snl24.com/kickoff from France.
"So it felt great to score. I have good communication with my teammates now. So it felt very nice and I was happy after the game.
"But it was unfortunate that I came here on loan with an injury. The coach [Faruk Hadzibegic] didn't know and he thought I was okay. I trained and it become worse and I was out for another month.
"It was a very bad start as a player and even now I am still recovering, I'm not a hundred percent fit. I still feel some pain when I'm sprinting, shooting. I'm still not hundred percent but it'll get better."
The Tembisa-born hitman hopes to make his Ligue One debut when he returns to Lille at the end of the season where he faces competition for game-time from Portugal's European Championship hero Eder.
"This loan deal will help me a lot because I'm here for game-time, to play and get confidence. Ligue Two is very strong, it's not easy.
"There's a similarity with Ligue 1, it is very physical. So I'm here for game-time, to play and get my confidence and when I go back to Lille I'll go there stronger."