Thompson elected to appeal his three-game suspension Tuesday, Meghan Montemurro of the Chicago Tribune reports.
Thompson was handed a three-game ban Monday for intentionally hitting Andrew McCutchen with a pitch Saturday. The appeal means he'll remain available for now, but it's still likely he's forced to miss up to three games sometime soon. If a resolution for his appeal doesn't come before the weekend, Thompson could pick up a start in Colorado on Friday, when the Cubs will require a fifth member of the rotation for the first time this season.