CHICAGO -- Cubs reliever Pedro Strop will not pitch again in the regular season after sustaining a moderate left hamstring strain running the bases on Thursday. Whether he'll get a chance to pitch in the postseason may depend on who picks up the slack as the Cubs closer for the remaining 16 games.
Strop was hurt running the bases in the 10th inning during the Cubs' 4-3 win over the Nationals. An MRI on revealed the strain on Friday.
"He's been so big for us now," Chicago manager Joe Maddon said. "To be without him for the next couple weeks will be difficult."
The Cubs have been trying to find a replacement since Brandon Morrow was sidelined July 18 with a bone bruise on his right arm. Strop was never officially named the closer but had handled most of the save situations. Who takes over now? The list of candidates include Justin Wilson, who was the Tigers' closer in 2017; Jesse Chavez, who is 6-for-19 in career save situations; Steve Cishek, who closed for the Marlins and Mariners, and Jorge De La Rosa, who has been one of the more consistent pitchers in the 'pen.

"We definitely have guys who are capable, no question," Maddon said. "It's going to be who gets the last three outs based on what happens before that, and we'll see how it all shakes out."
Maddon also would like to see C.J. Edwards handle some of that workload. He's 2-for-9 in his career in save opportunities.
"We cannot win without [Edwards]," Maddon said. "We cannot advance in the tournament without him pitching as well as he possibly can. You've got to keep putting him out there, you've got to rebuild his confidence. ... We've got to get Carl to pitch a solid three or four outs, which he's capable of doing."

Edwards has had problems regarding control, and walked more batters than the Cubs would like.
"I talk to him afterward, and I always tell him, 'You can get anybody out,'" Maddon said. "He's going through a moment now, but you can't run away from that. You look at the big picture. For us to be able to finish this off and go deep in the playoffs, he has to be a big part of that. You don't sit him on the bench or run away from him, because you're not going to do it without him."
Chavez said it's just a matter of getting the job done and not placing too much emphasis on the save situations.
"We need to stick to the execution part and not magnify the ninth," Chavez said.
Randy Rosario got his first career save on Thursday when he took over in the 10th.
"The difference is the situation and the adrenaline of the game," Rosario said Friday.

Strop gave Rosario some advice.
"I've been asking him, 'How does it feel when you close the game?'" Rosario said. "He was talking to me about the adrenaline and how you can control that."
Maddon understands being second-guessed on having Strop bat for himself in the 10th inning. The Cubs had taken the lead on Javier Baez's bunt single, which drove in Kristopher Bryant from third. If Strop had thrown more than 21 pitches and if the game was still tied, Maddon would've used a pinch-hitter.
"I knew that he was hurt and that was a pretty bad moment for me personally, but the last thing I saw [in that situation] was injury," Maddon said. "You're not even contemplating an injury.
"He said he was fine, and I believed him. It was just unfortunate that it happened."
• Morrow will throw a sim game on Saturday but even when he does return, the right-hander will not be inserted back into the closer's role because he has missed so much time.
"It's hard to force him into a situation he's not ready for," Maddon said.
"If I come back and throw really well and strong, maybe there are some times I could get in there late in situations," Morrow said, "but still [I probably can't do] the back to back. I don't think you can name me closer. That's more for the benefit of the other guys so nobody gets caught off-guard when you're in the ninth, and if I can't go in the eighth, they have somebody else who needs to get up."
Morrow feels the Cubs have the pitchers to handle the job.
"We've got a lot of good arms and guys down there with closing experience that I don't think there will be any hiccups putting Cishek in there or [Wilson]," Morrow said. "Rosario did a great job last night. There are a lot of guys who have stepped up in situations. We definitely have the arms to cover it."
• Kyle Schwarber had hoped to return to the Cubs' lineup on Friday, but his back is still sore. He did some work in left field with the athletic trainers.
"He is close," Maddon said. "I guess he was still not 100 percent comfortable fielding ground balls, but overall, he's doing a lot better."

• Anthony Rizzo wore his road uniform home on the Cubs' charter from Washington to Chicago after Thursday's game. His teammates didn't sit too close to him.
"It was a little smelly," Rizzo said of his uniform.
Baez joined Rizzo and also wore his road uniform home.

"Javy's always ready to play," Rizzo said. "He jumped on board."
It helped lighten the mood. Thursday's game was the 24th in a stretch of 30 consecutive days in which the Cubs have had a game scheduled. Their first off-day will be next Thursday.
"We came off a tough loss [to the Brewers on Wednesday]," Rizzo said. "You can hang your head or have fun with what we have to do. You could pout that we have to go to D.C., or have fun with it. I went from my communion to the baseball field and wore my slacks on the baseball field. It took me back to when I was a little kid."