Through the Reds media relations department, Votto declined to talk with reporters. He has maintained his rights to privacy, which have kept the details behind his absence unknown.
Before Votto returns to the Reds lineup, Baker confirmed the 25-year-old would go out on a Minor League rehabilitation assignment first.
"Sometime, relatively soon," Baker said.
Votto is batting .357 with eight home runs and 33 RBIs this season.
Meanwhile, injured starting pitcher Edinson Volquez has yet to throw off of a pitching mound since he went back on the DL with elbow tendinitis on June 2.
Volquez has increased his distances for long tossing to 95 feet. On Wednesday, he will throw from 110 feet and before he gets on a mound again, will eventually get to 125 feet.
"No pain," Volquez said. "I was worried about it. Not anymore."
Volquez said he was scheduled to be examined again soon by team medical director Dr. Tim Kremchek. The right-hander has been doing daily rehab at Kremchek's sports medicine facility.
"I'm tired. Every day in the morning I have to go to Kremchek's place and then come back here and jump in the pool and work out in the gym," said Volquez, who is 4-2 with a 4.35 ERA in nine starts. "I bet he loves me."
Since he came down with back spasms on May 16 that originally put him on the DL, Volquez pitched just one inning before the elbow issue sidelined him again. A quick return isn't expected and it's likely he would have to go on a rehab assignment before getting to start for Cincinnati.
"We have to rebuild him back up," Baker said. "That's not an around the corner thing. It's around a couple of corners."
The Reds played their 44th straight game without third baseman Edwin Encarnacion, who has been on the DL since April 28 with a chip fracture in his left wrist.
Encarnacion took 25 swings in an early BP session on Tuesday and reported no problems. It was the first batting practice he has taken since he had a setback 10 days ago.
Back then, Encarnacion was close to going on a rehab assignment but no plans have been made yet.
"We'll have to see if he gets sore afterwards or not," Baker said. "That's the key. When he comes back, we want to put him on a very fast track and not play a day, [have him sore for two days afterward]. That won't help him or us. You can mix and match for a while. But there comes a point that you want to go the original plan and the original starting field. You don't only want to, you need to."