Sebastian Thangmuansang is a Gokulam defender who has taken part in the majority of the team's I-League games in 2020/2021, making 11 appearances overall and playing 884 minutes. He has been selected in the starting XI in 10 of these appearances across their 15 fixtures and entered as a substitute on one occasion. Thangmuansang last appeared in a competition game on March 27, playing 90 minutes for Gokulam versus TRAU in a 4-1 victory. In total, he has recorded one league assist this season. He has been shown a yellow card once. Thangmuansang moved to Gokulam in July 2019 from NEROCA, for whom he made 17 league appearances in total.