New Philadelphia Phillies manager Gabe Kapler called on a reliever who had yet to throw a warm-up pitch on Saturday against Atlanta.
Kapler remained on the mound as Milner took some throws before leaving the bullpen. Braves manager Brian Snitker came out of the dugout to argue about the delay and was ejected by umpire Jerry Layne, the crew chief.
Layne said he was trying to protect Milner's health.
"For whatever reason the pitcher wasn't even getting ready," Layne told a pool reporter. "Who got crossed up, I'm not placing blame on anybody because I don't know. He just wasn't ready. Hadn't thrown a pitch. ... The last thing I want to do is get somebody hurt. It's already a messed-up situation."
Layne said a report would be sent to Major League Baseball.
"Whoever's at fault on the Phillies' side should have to answer to Major League Baseball," Layne said.
MLB determined that Layne handled the situation correctly, sources told ESPN's Buster Olney, adding that the Phillies will receive a formal warning letter from the league.
Kapler said Milner warmed up earlier in the game.
"Anytime we have a miscommunication, that miscommunication is my responsibility so I take full responsibility for it," Kapler said.
Milner said he was fine.
"I was healthy going into the game. I'm healthy now. I feel fine," Milner said, according to the Philadelphia Inquirer. "I wasn't sore going into today. I told him I was ready to go. It was just a miscommunication that I didn't get as many warm-up pitches that would be ideal. ... Fortunately enough I'm the kind of guy that can throw eight pitches and be fine."
It was Snitker's second ejection of the series.
"It was the first time I've ever been part of anything like that," Snitker said. "I think the time had expired and just felt like we should have been playing ball."
Milner, pitching for the third straight game, recorded only one out.
Kapler used 21 pitchers in losing two of the season's first three games.
The Associated Press contributed to this report.