CHICAGO -- The Cubs have placed closer Craig Kimbrel on the 10-day injured list with right knee inflammation and recalled right-hander Duane Underwood Jr. from Triple-A Iowa.

The Cubs don’t expect Kimbrel to miss much more than 10 days. Kimbrel said before Monday's game against the Athletics that he is confident he could pitch through the injury but doesn’t want to risk making it worse. Kimbrel felt discomfort after his outing on Saturday and underwent an MRI exam, which showed the inflammation.

Kimbrel had meniscus surgery on his left knee in 2016, but he said this issue isn't nearly as serious.

“Instead of making a bigger problem than it is, we’ll let it calm down and get back out there,” Kimbrel said. “It’s the smart decision to let it rest.”

General manager Jed Hoyer agreed.

“Hopefully, we have a lot more games, and getting him right and getting him dominating and feeling good and not having to change anything I think is the right thing,” Hoyer said.

The 31-year-old has nine saves in 11 chances with a 5.68 ERA in 14 games since he signed a three-year, $43 million deal with the Cubs in June. Kimbrel said Monday he felt like he was close to returning to the form that helped lead the Red Sox to a World Series title last year.

“Timing-wise, I was getting real close,” he said. “I was feeling really good. ... It’s unfortunate I have to take a little break, but hopefully it’s a good thing.”

Pedro Strop, who handled closer duties before the team added Kimbrel, is on the injured list with tightness on the left side of his neck, leaving Chicago's bullpen shorthanded.

Manager Joe Maddon said Monday that Strop is very close to being ready to pitch in a game situation but the Cubs have not set a definite timeline for that to happen or whether Strop will make a rehab appearance in the Minors before returning to the Cubs. Hoyer said he would likely have a discussion with Strop after Tuesday’s game about next steps.

Maddon said it’s “committee time” as far as lining up the bullpen until Kimbrel and Strop are healthy and that Brandon Kintzler, Steve Cishek and Rowan Wick -- and Kyle Ryan for the right matchups -– will all be in the mix for save opportunities. Maddon said Underwood is “here to protect us” and that he could see action in early blowout scenarios or in extra innings.

“Of course, you’d prefer not having to do this,” Maddon said. “But the guys having the experience in doing this, I think we’ll make it work.”

Morrow progressing

Reliever Brandon Morrow (right elbow, forearm) has been throwing from up to 120 feet, and the Cubs are getting good reports about how he is feeling, according to Hoyer. The Cubs remain “cautiously optimistic” about Morrow’s ability to return this season, which Hoyer said would be a “great shot in the arm.”

Morrow, 35, signed a two-year, $21 million contract in December 2017 to be the Cubs' closer, but he hasn’t pitched since July 15 last season. He was initially expected to return in May, but he's had some setbacks while rehabbing at the Cubs’ Spring Training facility in Arizona.

Zobrist update

Hoyer said the Cubs would talk through next steps for veteran utility man Ben Zobrist, who spent the weekend on a rehab assignment with Class A South Bend. Hoyer said Zobrist, who has been on the restricted list since May 8, would take time off between stints and that the Cubs will decide what’s next in the next couple of days.

“I think we’ve said all along this is going to be pretty fluid,” Hoyer said.