Major League Baseball (MLB) players do not wear mittens during games, but they do wear gloves or mitts to help protect their hands and improve their grip on the ball.
In baseball, gloves or mitts are typically worn by defensive players to help them catch and control the ball. The type of glove or mitt used by a player depends on their position on the field. Infielders, such as shortstops and second basemen, typically use smaller gloves with shallow pockets, which allow them to quickly transfer the ball to their throwing hand. Outfielders, on the other hand, typically use larger gloves with deeper pockets, which help them catch fly balls and line drives.
In addition to helping players catch and control the ball, gloves also provide some protection against injuries, such as getting hit in the hand by a pitched or batted ball. While gloves or mitts are not required by MLB rules, they are an essential part of the sport and are used by nearly all players at all levels of play.