Phillips directed a short tirade at C. Trent Rosecrans of the Cincinnati Enquirer before the game at St. Louis.
Phillips let loose at Rosecrans in the clubhouse, then interrupted manager Dusty Baker's pregame media session to make a few more comments.
The Gold Glove winner stuck his head into the doorway of Baker's office and singled out Rosecrans, saying, "I've found out your Twitter name now, dude."
Phillips sarcastically encouraged Baker to "Make them happy, Dusty" and threw in some expletives for the reporter who's "worried about my on-base percentage."
"That ain't my deal," Baker said, adding the dispute was between Phillips and Rosecrans.
The episode didn't escalate.
Asked about the incident, Rosecrans said: "It's not the first time it's happened in the clubhouse and it's not the last. Brandon had his say and I don't care. It won't change how I cover the team, or Brandon."
Phillips has a .310 on-base percentage for the slumping playoff contenders. He has 95 RBIs and has batted fourth for most of the season, hitting .355 with runners in scoring position.
After the third-place Reds lost 6-1 Tuesday night and fell 4½ games behind the NL Central-leading Cardinals, Phillips tweeted:
— Brandon Phillips (@DatDudeBP) August 28, 2013
Baker said he didn't mind the tweeting, and Phillips was moved to the second spot for the first time since opening day.
Rosecrans later tweeted that Phillips should perhaps hit somewhere else in the order other than second.
Phillips got off to a fast start in his new slot. He singled and scored in a six-run first inning and singled and scored in a three-run second as the Reds took a 9-0 lead.