CINCINNATI -- Cubs third baseman Kristopher Bryant was held out of the lineup for a second consecutive game on Sunday with a sore left shoulder and is considered day to day, with hopes a couple of days of rest will do the trick.

Because the soreness is in his non-throwing shoulder, Bryant suspects the injury stems more from swinging -- maybe a little too much -- while doing extra work in the cages between games. He started feeling it around five days ago, but is confident the setback is nothing serious.

"I've been in the cage maybe more than I usually am," Bryant said, adding that he's experienced this soreness before, as a college player and in the Minor Leagues. "It's nothing I'm seriously concerned about."

Bryant admitted he may have been a bit stubborn trying to play through it, but eventually the pain was lingering long enough that he needed to alert the medical staff.

"I felt like there's a negative to going in the training room and telling them you're hurt, but sometimes, it's what you have to do to get better," Bryant said. "I think this will pay off in the long run."

Bryant may need another day of rest when the team opens its series in Los Angeles Monday, but his availability for that game has not been determined.

"He's been battling it, but I really felt like giving him [Saturday] off would be fine for today," manager Joe Maddon said. "I talked to him and [head athletic trainer] P.J. [Mainville] afterwards and it's still a little ratty -- it's just not right. There's no sense in pushing that. I don't think it's going to be for long. I also thought he might be fine for today, so it's a day-to-day kind of thing."

Darvish to rehab Monday

Right-hander Yu Darvish , who has been on the disabled list since May 23 with right triceps tendinitis, will make a rehab start on Monday for the club's Class A affiliate in South Bend, Ind., located approximately four hours from Cincinnati.

Maddon estimated Darvish would throw four to five innings and could throw as many as 75 pitches, though "we'll play that one by ear also," Maddon said.

Roster moves

The Cubs made several roster moves before Sunday's finale in Cincinnati, optioning Saturday's spot starter, right-hander Luke Farrell , to Triple-A Iowa and placing left-handed reliever Rob Zastryzny on the 10-day disabled list with a lower back strain.

The club recalled right-handers Cory Mazzoni and Justin Hancock .

Also, right-hander Tyler Chatwood , who was scheduled to start Sunday's game, took the first flight out of Cincinnati to Chicago Sunday morning in order to be with his wife, who is delivering the couple's first child. As of game time, Chatwood had not officially been placed on paternity leave.

Mike Montgomery, who knew he could be called upon at the last minute and prepared accordingly over the weekend, started in Chatwood's place.

Maddon said he received a phone call from the Cubs' traveling secretary around 5:30 a.m. ET Sunday, informing him that Chatwood was on his way back to Chicago. Chatwood then called Maddon, who said, 'Of course, man, go. We'll figure it out.'"

"He sounded like an expectant father," Maddon chuckled.

Alyson Footer is a national correspondent for MLB.com. Follow her on Twitter @alysonfooter.