CHICAGO -- The Cubs must have walked under a ladder somewhere along the line, because their bad injury luck continued following Sunday’s 5-1 loss to the Reds.

It was revealed that Trevor Williams, scheduled to start Monday's series opener against the Padres, had an emergency appendectomy on Sunday morning and will be out indefinitely.

“Our starters have been throwing the ball well. Obviously, with Trevor going down, that's a hit for us,” Jake Arrieta said. “We wish him a speedy recovery.”

Williams joins a long list of injured Cubs as May comes to a close.

David Bote was placed on the 10-day injured list earlier Sunday after dislocating his left shoulder on Saturday, making him the 11th Cubs player on the IL. Anthony Rizzo is still on the active roster, but the first baseman missed his fifth consecutive game due to tightness in his lower back on Sunday.

• Injuries/Moves: Bote lands on IL (shoulder)

“There's a long list in there. There's like 11 or 12 guys in my report in the morning,” Cubs manager David Ross said. “Keeping track of all of them is getting a little daunting.”

The Cubs are expected to announce a move involving Williams on Monday. If Williams is forced to miss extended time, Alec Mills (scheduled for another rehab start this week) or Keegan Thompson could be options to fill in against the Padres. Kohl Stewart could also be called up from Triple-A Iowa.