Westervelt made his MLB debut on April 21, 1894, at the age of 24.

He pitched in 23 games for the Giants that year, starting 18 of them and posting a record of 7–10 with a 5.04 earned run average.

He also had 11 complete games, and his single shutout tied him for seventh most in the National League that season.

He played his final MLB game on August 11, 1894.

This biographical article relating to an American baseball pitcher born in the 1860s is a stub.