CHICAGO — The Chicago Cubs will have to get by without closer Brandon Morrow for at least a little while.

The Cubs placed the right-hander on the 10-day disabled list Wednesday because of lower back tightness, leaving a short-handed bullpen without its most important piece.

While Morrow went on the DL, Yu Darvish threw a simulated game. Manager Joe Maddon said he looked “outstanding,” and the Cubs will see how he feels Thursday before announcing the next step as he works his way back from tendinitis in his right triceps.

Morrow – signed by Chicago to a $21 million, two-year contract in December after helping the Los Angeles Dodgers beat the Cubs in the NLCS – has 16 saves in 17 chances.

He hurt his back on Monday. The Cubs put him on the DL before their game against the Dodgers and announced right-hander Justin Hancock will remain with the club after being called up from Triple-A Iowa as the 26th man for Tuesday’s day-night doubleheader.

The Cubs are also missing relievers Carl Edwards Jr. (right shoulder inflammation) and Brian Duensing, who is on the bereavement list after his grandfather died Saturday.

INDIANS: President Chris Antonetti said left-hander Andrew Miller (right knee inflammation) is throwing bullpen sessions, but not ready to go on a minor league rehab assignment.

“He has to go through a progression to get back to game activity, and he’s not there yet,” Antonetti said.

Miller is 1-3 with one save and a 4.40 ERA in 17 appearances. The two-time All-Star has been on the disabled list since May 26.

CARDINALS: Right-hander Michael Wacha left Wednesday’s start in the bottom of the fourth against the Phillies with a left oblique strain.

YANKEES: Billy Connors, a three-time Yankees pitching coach and confidant of late owner George Steinbrenner, has died. He was 76.

The Yankees said Connors died Monday. The team held a moment of silence before their game Wednesday night against the Seattle Mariners at Yankee Stadium.

Connors coached the Yankees from 1989-90, 1994-95 and 2000, and was vice president of player personnel from 1996-2012. He was instrumental in the development of Yankees pitchers Orlando Hernandez, Andy Pettitte, Chien-Ming Wang and Mariano Rivera.