Singh was fielding at the boundary line near the Divecha stand when the two spectators jeered at him for not picking up a wicket during the first session of the day.
The 32-year-old, who picked up two wickets in his 21 overs, reported the incident to Mumbai Cricket Association authorities who later complained to the Marine Drive police personnel present on the ground.
"The police arrested the two spectators and let them off with a warning," an MCA official said.