He plays in the national league, so wouldn't he be in the batting line up every day he pitches? They make such a big deal out of him batting in what would be the middle of the season, but he would have had to step in the box every time he started. This is an egregious continuity error.
shareHe wasn't a starting pitcher, he was a reliever (specifically, a closer I believe). It's rare for a relief pitcher to even get a couple at-bats in an entire season (due to having appearances that only last an inning or less and/or double-switches to move their spot in the batting order).
--I'm going to make out in the coat room, don't eat my chicken.
--That's going on your tombstone.
The idea was to show him as a pitcher, not as a batter. Yeah, he did bat again and again, but that wasn't important.
shareThere are plenty of continuity errors in this movie, but this isn't one of them. He was a reliever, and he was asked by the manager to pitch a second inning in relief. After his first inning pitched, and before he started his second inning, his spot in the batting order was due up.
Normally relievers are pinch hit for, but since his manager wanted him to pitch a second inning, he needed to bat for himself so he could stay in the game. This scenario is rare for a reliever, but it does happen occasionally. Hope this answers your five year old question.