Sean Marshall will undergo surgery Tuesday to debride his left shoulder. The Reds haven't revealed how long Marshall will be sidelined after the procedure, but it will surely be a season-ending operation. Marshall held a 7.71 ERA before landing on the DL last week and has been limited to just 31 appearances over the last two seasons due to shoulder issues. He's slated to earn $6.5 million from the Reds next season.