Possible Clues:

• One disagrees with one book having zero pages at the front
• Quietly working in public, start to torment rival
• 1 that not 4U
• Contestant you're matched against
• One from the other side
• Adversary, competitor
• Work quietly on bridge bid, doing for member of other team
• Eton falsely admitting pressure doubled on rival
• Challenger
• By the sound of it, not before you this one