The Padres opening day roster has 12 pitchers, two catchers, five infielders and six outfielders.

It is missing one pitcher.

Nick Margevicius, a 22-year-old left-hander who has pitched one game above Single-A but impressed the Padres in spring training, will start for the Padres on Saturday, according to a source. He does not have to be added to the roster until then.