Related Clues:

• Ones ranked E-4 to E-9: Abbr.
• 'Ball!' callers
• Sgts., e.g.
• Sgt. maj. and others
• Strike callers
• Cpls. et al.
• Ballpark figures
• E-4's, E-5's et al.
• Sgts. and cpls.
• Base runners?: Abbr.
• They make a lot of calls
• Rank leaders?: Abbr.
• They cover the bases
• Diamond experts
• They stand behind catchers