The hard-throwing reliever, who flew to Baltimore in the morning and arrived at the ballpark in the late afternoon, pitched a scoreless eighth inning in the Yankees' 6-0 loss to the Orioles. Chamberlain said his father was doing much better.
"What a day. I was at the hospital this morning, took a flight here, got on my uniform and went out to get warmed up," he said. "It was nice to be back with the team."
Manager Joe Girardi said Chamberlain threw while he was in Nebraska.
"He's glad to be back," Girardi said. "The good news is that if he is back, his dad must be getting better."
Harlan Chamberlain collapsed at home April 14 and was hospitalized and put on a ventilator. Joba Chamberlain flew home that day and was placed on the bereavement list by the team.
Harlan Chamberlain was taken off the ventilator Friday night.