A manager at MCU Park noticed the defacement Wednesday morning. The words "Heil Hitler," an expletive and racist epithets were scrawled on the statue in black marker. Workers later covered up the vandalism.
Police are investigating it as a hate crime and are hunting for video evidence.
The statue is of Robinson and his Brooklyn Dodgers teammate Pee Wee Reese.
MCU Park in Coney Island is the stadium for the Brooklyn Cyclones, a minor league affiliate of the New York Mets. The team marked the return of professional baseball to Brooklyn, which lost the Dodgers to Los Angeles in the late 1950s.