Olimpija Ljubljana boss Marko Nikolic has been widely reported as calling Blessing Eleke a "black idiot" after he felt the Nigerian, 20, spent too long celebrating an equaliser.
The club initially refused to suspend the Serb, but the Slovenian FA intervened "because of clear racism".
Olimpija are two points clear.
The game against Zavrc ended 1-1 thanks to Eleke's first home goal for Olimpija following his January move from league rivals Gorica.
Nikolic said he made "an emotional reaction" as Eleke's celebration meant there was less time for a winner against and "never intended to offend the player racially".
He added: "I spoke to Eleke and he said he understood my reaction because emotional outbursts of this kind can happen.
"I apologise for my reaction generated solely by the rush to score the winning goal after getting a 92nd-minute equaliser and I thank the team for not judging my act as racist."
Olimpija president Milan Mandaric, the former Leicester and Portsmouth owner, had defended Nikolic, saying: "We have come to the conclusion that the coach did not target the player's race."
The coach of Slovenia's league leaders has been banned for the final seven games of the season for racially abusing one of his own players.