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.

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

The Reds broke a scoreless tie by getting five straight singles off reliever Manuel Corpas (0-2) in the seventh during a five-run rally capped by Henry Rodriguez’s two-run double.

Chicago starter Jason Berken gave up just two hits in six innings.

“I was able to get a couple of jams, great defense behind me, stayed on the same page the whole game,” Berken said.

Cueto gave up five hits with four walks and broke a three-game losing streak.

“I don’t think that was the best stuff he’s ever had. You can tell he might be getting a little tired at the end of the year or whatever, but I’ve seen him with a lot better stuff,” Chicago manager Dale Sveum said.

The Cubs scored in the seventh on Anthony Rizzo’s RBI single and in the eighth on Welington Castillo’s fifth homer again.