Team Chief Operating Officer Jeffrey Wilpon made his argument on the club's behalf in court papers filed Friday in federal court in Brooklyn.
Leigh Castergine sued Wilpon and the club earlier this year. She sought unspecified damages, saying she was fired after enduring insults and humiliation. Her lawsuit said Wilpon told senior executives he was "morally opposed" to her having a baby while unmarried.
She was hired in December 2010 as vice-president of ticket sales and service. She said she was subjected to discrimination after learning she was pregnant in August 2013.
She was fired a year later.