CHICAGO -- As the Reds near the end of the regular season and prepare their rotation for the postseason, there is no chance that September callup Tony Cingrani will get a start.

Cingrani -- a left-handed starter who split this season at Class A Bakersfield and Double-A Pensacola, and ranked by MLB.com as the Reds' No. 3 prospect -- threw 146 innings in the Minors and is near his innings limit.

"We didn't bring him up here to be a starter," Reds pitching coach Bryan Price said on Wednesday. "We didn't bring him up here to be a guy who inherits a lot of innings during his stay. We certainly feel, for a guy who is an experienced relief pitcher and being short from that side, that he could give us some support in a more limited role."

Cingrani has experience as a closer from his season at Rice University. As for whether he would get consideration for the postseason roster, Price declined to say.

"I don't think it's something I should talk about," Price said. "I'll let Dusty [Baker] talk about it."

Baker hospitalized with irregular heartbeat

CHICAGO -- Reds manager Dusty Baker was hospitalized on Wednesday afternoon and diagnosed with an irregular heartbeat. He will remain in a local hospital overnight and have more tests performed on Thursday morning.

Baker left Wrigley Field to have a chest X-ray performed to rule out pneumonia. Bench coach Chris Speier managed in his place for a 6-5 win over the Cubs in 11 innings. Speier will also manage for Baker on Thursday.

"I guess the good thing is it's not pneumonia, but the bad thing is he's got an irregular heartbeat," Reds head trainer Paul Lessard said. "Basically he had a heavy feeling. He wasn't breathing well. We just decided to look into it a little further. He's had a history of an irregular heartbeat for a while, so it doesn't really bother him. That's why he was kind of poo-pooing it."

Baker, 63, was seen by a member of the Cubs' medical staff -- Dr. Stephen Adams -- before departing for Northwestern Memorial Hospital. He was instructed to get some rest.

There were no outward signs that Baker has felt ill lately. He was in the clubhouse chatting with a couple of his players during the afternoon before the team took the field for batting practice.

The players were informed of Baker's condition during a team meeting.

"You know I had to worry about my daddy. I can't have daddy passing out on us, man," second baseman Brandon Phillips said. "I'm glad he's all right. He's going to be in our prayers. I'm going to pray for him when I get back to the hotel.

"Hopefully he's back soon. I miss him and the toothpicks and the wristbands. I miss it all."

Speier and other members of the club front office spoke to Baker after the game, and he reported that he was feeling fine.

"He sounded good," Speier said. "They're just doing their due diligence and running some tests. He'll be back shortly."

On Tuesday, in a 3-1 Reds win over Chicago, Baker managed the 3,000th game of his career.

Ludwick exits as precaution with groin tightness

CHICAGO -- Reds left fielder Ryan Ludwick was removed from Wednesday's game against the Cubs as a precaution because of left groin tightness while running the bases.

Ludwick, who was 1-for-2 with an RBI single in the third inning and a walk in the top of the fifth, was lifted for Chris Heisey to begin the bottom of the fifth inning, with the Reds leading, 5-1. He also made a nice sliding catch of Darwin Barney's fly ball in the fourth.

Ludwick is batting .276 with 26 home runs and 80 RBIs this season.

Chapman throws successful bullpen session

CHICAGO -- For the first time since he was shut down with left shoulder fatigue, Reds closer Aroldis Chapman threw in a side bullpen session on Wednesday.

Chapman threw 25 pitches and reported no issues.

"It went real well," Chapman said via interpreter. "I was throwing normal as a bullpen. When you throw a bullpen, you don't throw 100 percent, you never do that."

Chapman was supervised by pitching coach Bryan Price, assistant pitching coach Mack Jenkins and two trainers. Price was pleased with what he saw.

"He threw the ball well -- no inhibitions, no shoulder fatigue," Price said. "It was crisp. Repetition certainly helps. It's hard to go a week without throwing off of the mound and feel completely acute. But the arm really worked well. The velocity and rotation was good."

Chapman, 24, struggled in his last two appearances for the Reds and hasn't pitched since walking three batters in two-thirds of an inning on Sept. 10 vs. the Pirates. But the shoulder issues seem to be behind him.

"It feels good," Chapman said. "I feel like I need to throw 2-3 more times to work on my command. I don't feel like I have the command the way it is."

Chapman is scheduled to play catch on Thursday. It's possible he could return to closing games sometime this weekend, when the Reds host the Dodgers.

"Once we get home, we'll take a look at it," Price said.

Worth noting

• Ryan Ludwick's 34 RBIs at Wrigley Field over the past five seasons are tied with the Brewers' Ryan Braun for the most by any player in baseball.