CHICAGO — The Chicago Cubs placed closer Craig Kimbrel on the 10-day injured list Monday and announced All-Star catcher Willson Contreras will be sidelined for four weeks with a right hamstring strain.

The pair of injuries will test Chicago’s depth and the ingenuity of its front office as it tries to win the roller-coaster NL Central for the third time in four years. While manager Joe Maddon can turn to Steve Cishek and Brandon Kintzler while Kimbrel is out, the catching situation is more perilous and the team can’t trade for help under a new set of rules that began this year.

Kimbrel, who got a late start this year after he finalized a $43 million, three-year deal with the Cubs in June, is dealing with inflammation in his right knee. He said it started bothering him while he was closing out Saturday’s 4-1 victory over the Brewers.

“We assessed it yesterday morning and it looked like there was a strain and some swelling in there and we’re just going to let it calm down,” Kimbrel said before Chicago’s series opener against Oakland. “Instead of trying to throw through it, which I’m pretty confident that I could, instead of making it a bigger problem than it is, just letting it calm down.”

Kimbrel had a meniscus surgery on his left knee in 2016, but he said this isn’t nearly as bad. The IL stint is retroactive to Sunday, and he thinks he will be ready when he is eligible to return.

“This is just some discomfort that I’m going to get some time and then everything should be fine,” he said.

Kimbrel is 0-2 with a 5.68 ERA and nine saves in 14 games. But the right-hander felt he was getting closer to his usual form of late, posting scoreless outings in 10 of his last 11 appearances.