The Boston Celtics saw their season change right before their eyes before a 1980 preseason game — on a bus. The Celtics were on their way to a game against the Chicago Bulls and were sitting in their bus that never moved. Veteran center Dave Cowens asked head coach Bill Fitch to step off the bus so he could have a word with him.

When they returned to the bus, Cowens was no longer a member of the team. He abruptly retired, shocking many players, especially second-year star Larry Bird. When he heard the news, Bird turned his head, looked directly at newcomer Robert Parish and delivered a brief, but stern, message.

Larry Bird was shocked at the abrupt retirement of Dave Cowens

The Boston Celtics were fresh off a season in which they won an NBA-best 61 games, 32 more than the previous year. Larry Bird played a big part in that turnaround, earning Rookie of the Year honors after averaging 21.3 points and 10.4 rebounds.

Although in his ninth season, Cowens was still plenty effective, putting up 14.2 points and 8.1 rebounds. That’s what made Cowens’ retirement news so shocking.

“We were sitting on the bus, waiting to leave for a game with the Chicago Bulls in Evansville,” Bird said in his book Drive: The Story of My Life. “After a while, it seemed as if we should have left already, and people were saying, ‘Come on, let’s go.’ Then Dave walked on the bus and asked Coach Fitch to come outside so he could have a word with him.

“We still didn’t have a clue. Dave gets on the bus and says, ‘I’ve got to tell you something.’ Then he proceeds to make a speech. Dave says, ‘I want to wish you luck, but I think it’s time for me to retire.’”

An undersized center, Cowens may be the most underappreciated Celtics player ever. At 6-foot-9, he had to square off against much bigger and more physical players throughout his career. He more than held his own, helping the Celtics to a pair of championships. Cowens was also the NBA’s MVP during the 1972-73 season after averaging 20.5 points and 16.2 rebounds.

As soon as Bird heard the news, he turned to Parish

After the 1979-80 season, the Celtics held the top pick in the 1980 NBA Draft from a previous trade. They traded that pick, along with the 13th selection, to the Golden State Warriors. In return, the Celtics received Robert Parish and the No. 3 pick. With that third pick, they selected Kevin McHale.

With Cowens gone, the Celtics needed an instant contribution from Parish. Seated three rows ahead of Parish on the bus, Bird turned around and addressed Parish.

“You better get into shape,” Bird said, per Jackie MacMullan’s book When the Game Was Ours.

“I was a little mad. I thought we had a great team with Dave. But without him? Robert wasn’t ready. And Kevin? Who knew, really?”

Parish knew he was out of shape.

“Coach Fitch set the mindset during training camp,” Parish said during a 2020 appearance on The Cedric Maxwell Podcast. “Toughest training camp I’ve ever been in. I was out of shape, and I’ll be the first to admit that because I did not prepare properly. Oooh, it was grueling. I’m not gonna lie.”

Parish dug in and played a key role in helping the Celtics win the first of their three championships of the decade that season.