No rules against it, but the Cubs could just take the walks until they got a safe lead, and then swing at every pitch even if it was 5 feet outside in order to strike out and end the inning. and then the cardinals miss the 3rd strike on purpose so it goes to the backstop. Then the Cubs' batter doesn't run to first base, and Molina doesn't go back to retrieve the ball. It'd be hilarious. It's like the South Park episode, when they are tired of playing baseball so they try to lose on purpose.