Hader, a Millersville native and Old Mill graduate, spoke with teammates before a game Friday against the Los Angeles Dodgers , the first action for the Brewers since the All-Star break.
"I just want them to know that I'm sorry for what I did back in the day and the mistakes that I made," Hader said, "and that they are a family to me and that they (the tweets) aren't me and what I meant."
Outfielder Brett Phillips said Hader offered a sincere apology. Manager Craig Counsell described Hader as emotional and remorseful.
Hader expressed regrets again during a news conference about 90 minutes before the game. Teammates filed into the Miller Park media auditorium as Hader spoke, with fellow All-Stars Jesus Aguilar and Lorenzo Cain among those who stood directly behind Hader.
"It's amazing. It tells me that they have my back and that we are a true family," Hader said about the show of solidarity.
The 24-year-old Hader also apologized and took responsibility for the tweets after the All-Star Game, saying they did not reflect his values or the person he is now.
The tweets included uses of a slur used to disparage African-Americans and one that simply said "KKK."
Said Hader: "They were never my beliefs. I was young. I was saying stuff out of just ignorance and that's just not what I meant."
Until Tuesday, Hader was best known as the hard-throwing left-hander in the Brewers' strong bullpen. The former Orioles prospect and draft pick had been a lights-out reliever since coming up to the majors in June 2017.
Hader's 6-foot-3 frame, long hair and glasses gave him a unique look on the mound. A filthy fastball and knee-buckling slider allowed Hader to strike out 89 in just 48 innings.
Several of Hader's tweets from 2011 and 2012 were unearthed Tuesday while he was pitching in the All-Star Game. Hader learned of the situation when he left the game.
MLB announced Wednesday that the commissioner's office would require Hader to participate in diversity and inclusion initiatives in addition to sensitivity training.
A day filled with acts of contrition by Hader also included a meeting with Billy Bean, MLB's vice president for social responsibility and inclusion. He described Hader as "punishing himself more than probably anyone else could."
"I was really convinced after a couple hours together today — much longer than we expected — that his experience as an athlete and a professional in an integrated, diverse environment has created the person that he is today," Bean said.
"I believe that, much like many of our millennial youth, he just probably forgot about whatever that moment was in his adolescence," Bean added.
The tweets stirred a range of emotions among some players who took part in an optional workout on Thursday that did not include the Brewers' five All-Star representatives. Teammates voiced support while also wanting to hear from Hader.
They had Hader's back after the reliever's apology Friday.
"Today was big for him. A sincere apology was needed and he did — you could tell in his voice that he's very, very sorry," said Phillips, Hader's roommate for the past four years. They have lived together since their days in the Astros organization before being traded to the Brewers in 2015.
"Not once — not once — has he said any of those (things) behind closed doors to myself or to anyone who's close with him. Looking at those tweets, he's come a long way," Phillips said. "Obviously you can see the growth. If you believe that people can change for the worst, then you believe that they can change for the best."
The next step for Hader is getting back on the mound. Following an emotional day for the reliever, Counsell said he didn't know whether Hader might be ready to pitch Friday.
It's unclear what kind of reaction he might receive from the crowd.
"This isn't me," Hader said when asked if he had a message for fans. "I hope that people who I've touched and came across, they know who I really am. I've made mistakes. I'm not perfect. I've grown as a person. Baseball really helped me grow."