CHICAGO >> Dusty Baker was missing when the Cincinnati Reds became the first team in the majors to clinch a playoff spot. The main man in the dugout was sidelined Thursday for a second straight game after being diagnosed with an irregular heartbeat.

“Obviously we won the last two games for him. We have him in our thoughts, but we got good news on his update,” reliever Sean Marshall said after a 5-3 victory over the Chicago Cubs.

“Hopefully he’ll be back with us tomorrow and when it really matters, when we clinch (the division). Hopefully we get to celebrate this weekend with him,” he said.

Ace Johnny Cueto and the NL Central leaders ensured themselves of at least a wild-card spot. Cincinnati cut its magic number to two for winning the division for the second time in three years.

The Reds said Baker would remain in a Chicago hospital for an additional day so doctors could monitor his progress. The manager left Wrigley Field before Wednesday night’s game and underwent another test Thursday.

Baker is expected to return to Cincinnati on Friday. Bench coach Chris Speier ran the team for a second straight game.

“He looked good. Very good. He’ll be there tomorrow,” said general manager Walt Jocketty, who visited Baker on Thursday morning. Jocketty said he didn’t know if Baker would be able to manage when the Reds open a series at home against the Dodgers.

“”Chris Speier did an excellent job, but I think he’s (Dusty) missed and we’re looking forward to having him back, and more importantly, we’re hoping for the best with his health,” star first baseman Joey Votto said.

“I know he’s excited and happy, just wish that he was here to partake in it, but he’ll be back soon,” Speier said.

Cueto (18-9) pitched six shutout innings as the Red completed a three-game sweep.