Possible Clues:

• A substitute
• Perform as substitutes in Test and international
• Wrong about function taken by daughter substitute
• Deputise
• It could be night-watchman is stumped and given not out
• Stunt double, for one
• With 55-Across, be punished at school, old-style ... and a hint to this puzzle's circled letters
• Deputy who evidently doesn't stand out
• Relief when fools get sent back and put inside
• Dan isn't prepared to become a locum