Baker also received fluids Friday, being treated for an irregular heartbeat.
Bench coach Chris Speier, who has filled in as acting manager in Baker's absence, said Baker was expected to return to Cincinnati at some point Friday.
"I think bottom line, I'm worried," Speier said. "You have your good, good close friend that's in the hospital. He's fine, it's just, they want to make sure before they put him on the plane that he had some fluids and make sure that's all taken care of. But you worry about him. He's our leader, and for me just a dear, dear friend. My mind is more with him than it is about this game."
Baker went to the hospital before Wednesday's game in Chicago, and Speier managed the club since.
Speier last spoke with Baker on Thursday, and the two hadn't spoken as of Friday afternoon.
"I know that he hasn't got much rest," Speier said. "Being in the hospital, they poke and prod you every hour. Out of respect for his rest and what he needs to do, I've backed off. I think there's such a trust built up between us that he knows things will be taken care of here."
It's not just the Reds' clubhouse showing their concerns for Baker.
When word traveled to San Francisco, where Baker managed for nine years, Giants manager Bruce Bochy sent his regards.
"Dusty and I are good friends," Bochy said. "Hopefully, he'll become well and return to the field pretty soon."
Rangers manager Ron Washington was also pulling hard for Baker to make a full recovery.
"Dusty Baker, when I first got to the big leagues, was my mentor," Washington said of his former Dodgers teammate. "Jeffrey Leonard and I came up in 1977, and Dusty showed us the ropes around the league. We've been friends ever since. I talk to him every now and then, asking for advice. I'm certainly hoping for the best for Dusty."
But Baker's absence is certain felt around Cincinnati.
"Dusty, obviously, has been our leader," Reds shortstop Zack Cozart said. "He's done a great job, and we're thinking about him. Everybody comes in and asks about him and asks how he's doing. We wish he was here. Got to win one for the skipper."
Mark Clements is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.