A manager, two coaches, and a veteran catcher gathered near home plate about four hours before Monday's game to watch Jorge Alfaro. The 23-year-old catching prospect fired again and again to second base in a pregame drill, showing an arm that is regarded as one of the best in the minors.
On Tuesday, Alfaro will have a chance to use it in a major-league game.
He will catch Alec Asher, in what should be the first of a few opportunities for the Colombian catcher this September.
The Phillies have 18 games remaining after Monday. Alfaro could start between six and eight of those games, Phillies manager Pete Mackanin said.