CHICAGO -- The number of Cubs players on the injured list reached a dozen on Monday morning, when pitcher Trevor Williams was shelved due to appendicitis.

Prior to Monday's game against the Padres, Chicago placed Williams on the 10-day IL (retroactive to Friday) in the wake of the pitcher's emergency appendectomy on Sunday morning. Righty Kohl Stewart was recalled from Triple-A Iowa to start against San Diego.

• Cubs Injuries & Roster Moves

"You just want to cry 'uncle' sometimes," Cubs manager David Ross said on Monday morning. "But, it is what we're dealing with. Guys have done a nice job of coming up and helping us win ballgames. Not going to complain about it -- just move through it. Your heart goes out to the players."

There is currently no established timetable for return for Williams, who has a follow-up exam later this week, per Ross. After that consultation, the Cubs should have a better sense of how much time the right-hander could miss before rejoining the rotation.

In 10 starts this season, Williams had a 5.36 ERA with 49 strikeouts against 20 walks in 43 2/3 innings. The righty, who has logged a career-best rate of 10.1 strikeouts per nine innings, worked six frames (one run allowed, seven strikeouts, no walks) in a win over the Pirates on Wednesday.

Stewart offered an option already on the 40-man roster, which no longer includes starters Tyson Miller or Shelby Miller. Both right-handers were designated for assignment within the past week to clear room for other injury-related transactions.

The Cubs will take a look at Stewart (signed to a one-year MLB contract over the offseason), while also giving righty Alec Mills (10-day IL, back) time to continue his Minor League rehab at Triple-A. Righty Keegan Thompson is also a starter by trade, but has been a key part of Chicago's bullpen.

"We'll take it day to day," Ross said of the rotation situation. "We'll take it one at a time for right now."

Three Cubs on the mend

Prior to Monday's game, outfielders Jason Heyward (10-day IL, left hamstring) and Jake Marisnick (10-day IL, right hamstring) both went through running and agility drills and took batting practice on the field at Wrigley Field.

First baseman Anthony Rizzo, who has been out of the starting lineup for the past six games due to a back issue, also went through a pregame workout (agility work, fielding grounders and BP).

"We're on the verge of getting some guys healthy," Ross said, "which is the good news on the back end of some bad news."

Down on the farm

• Triple-A Iowa: Right-hander Cory Abbott (No. 15 on MLB Pipeline's Top 30 Cubs prospects list) struck out 13 with one walk in six innings against St. Paul on Sunday.

• Double-A Tennessee: Catcher Miguel Amaya (No. 3) had one hit, two walks and three runs on Sunday against Chattanooga.

• High-A South Bend: Outfielder Brennen Davis (No. 2) went 3-for-5 with two runs and infielder Chase Strumpf (No. 9) went 2-for-4 with an RBI against Fort Wayne.

• Low-A Myrtle Beach: Outfielder Jordan Nwogu (No. 27) hit his first professional home run against Salem.

Quotable

"The tough part, you just get text messages at two in the morning from [the] doc about some of your players being in surgery and you just worry about them. That's the main concern." -- Ross, on the past week of injury setbacks