ATLANTA — After blowing a six-run lead Wednesday night, Roy Halladay left the Phillies to tend to a personal family matter. The absence was planned before his outing. He is expected to rejoin the team Friday in Washington.

Phillies assistant general manager Scott Proefrock said Halladay told both manager Charlie Manuel and pitching coach Rich Dubee on Tuesday he would need to leave.

After addressing reporters late Wednesday night following the 15-13 loss, Halladay departed Turner Field with a small rolling suitcase. The righthander said he was physically fine although his face turned bright red as he labored through the final two innings.

"Honestly, I felt good," Halladay said. "There were some pitches with guys on that I didn't execute. It had nothing to do with anything else. I wish I had a better reason for you, but I don't. It was just a lack of executing pitches in key situations. That's what cost me."

Pitching coach Rich Dubee admitted he does not believe Halladay's pitches are always "accelerating through the hitting zone." Since that is physically impossible, Dubee was more than likely referring to a decrease in Halladay's velocity. At times, Dubee sees the usual life and movement.

"The others," Dubee said, "he's just throwing a few cement mixers. … It just wasn't a good night."

The telling sign will be whether that can be reversed during his next start, Monday against the Mets. If not, it could create a disturbing trend. Halladay's velocity has dropped in 2012, but the results had not — until Wednesday.

Halladay required only 46 pitches to complete the game's first four innings. It turned sour in the fifth. What happened?

"I don't know, man," catcher Carlos Ruiz said Thursday. "Everything happened real quick. He made good pitches but I give credit to their hitters. They were looking for the pitches he threw. They didn't miss them. Everything happened real quick."

Before the shocking fifth, Halladay had not allowed six runs in one inning since May 10, 2007. Dubee said he thought about not letting Halladay pitch the sixth, in which he allowed two more runs before being yanked.

"But we're also talking about a different animal," Dubee said. "He has that innate ability to bounce back from a tough inning and regroup and get going again."

Contact Matt Gelb at mgelb@phillynews.com or follow on Twitter @magelb.