The bench jockey shouted insults at the opposing pitcher.
bench jockey
idiomA player, coach or manager who verbally annoys and distracts opposition players and umpires from his team's dugout bench.
Origin
disputed originAs verbal jousting is frequently called "riding", the "rider" sitting on a bench came to be known as the "bench jockey".
The umpire warned the manager because a bench jockey kept yelling at the players during the game.
Known throughout the league as a relentless bench jockey, he spent the entire afternoon taunting the visiting team from the safety of the dugout.