CBS microphones picked up the exchange during its live broadcast of the match.
Tournament spokesman Chris Widmaier says Federer is being docked the same amount as two other players Vera Zvonareva and Daniel Koellerer for audible obscenity.
Widmaier says a total of $31,500 in fines is being collected by the tournament, topped by Serena Williams $10,000 for unsportsmanlike conduct. She was also fined $500 for racket abuse. Daniel Nestor was docked $5,000 for unsportsmanlike conduct toward a fan.