The 29-year-old was on Sunday not pleased with the umpire's leg before wicket decision off Sunil Narine and showed anger while walking back to the pavillion, when his team needed 105 runs off 62 balls.
Despite the fall of wickets at regular intervals, Mumbai managed to pull off a thrilling four-wicket win against Kolkata to continue their dominance over their rivals.
"Rohit Sharma, the Mumbai Indians captain, was reprimanded by the match referee for showing excessive, obvious disappointment with an Umpire's decision during his team's contest against the Kolkata Knight Riders at the Wankhede Stadium," an Indian Premier League (IPL) statement said.
"Mr Sharma admitted to the Level 1 offence 2.1.5 of the IPL Code of Conduct for Players and Team Officials.
"For Level 1 breaches of the IPL Code of Conduct, the Match Referee's decision is final and binding," it added.
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