infielder
US /ˈɪnˌfiːl.dɚ/
UK /ˈɪnˌfiːl.dɚ/

1.
a player in baseball or softball who plays in the infield (between the bases)
:
•
The shortstop, a skilled infielder, made a diving stop to save a run.
•
The coach praised the infielder's quick reflexes.