Factual error: The gas ratio sticker on the car was an A sticker which was only 3 gal. of gas a week. Unlikely they could go from IL to OR on that small amount of fuel.
Factual error: In some scenes during the games, the sun is in the direction of right field shining towards home plate. In professional baseball games, this is never allowed due to the sun being in the batters eyes. Side note: This is why no ballpark in major leagues ever had home plate on the east side of stadiums when they were built.
Answer: Rosie O'Donnell auditioned for the role of Marla, but lost it. Penny Marshal thought she was a good actress and so funny she created the role of Doris for her. As for Madonna, she was like all singers getting offered movie roles. She was very popular back in the 90's, but reportedly a total diva to work with.