Bill Sharman is no basketball radical. He was not trying to revolutionize the N.B.A. when he became the Los Angeles Lakers’ coach in 1971. He simply wanted his players to be confident, relaxed and mentally sharp on game nights. So Sharman instituted a brief morning practice and gave it a lively name: the shoot-around.

Within a few years, every team in the league was holding them.

Doc Rivers is no basketball revolutionary. He simply wants his Boston Celtics to be confident, relaxed and mentally sharp on game nights. So a couple of months ago, Rivers eliminated morning shoot-arounds.

The Celtics, who lead the Eastern Conference with a 20-5 record, hardly seem to miss them.

“All of them, to a man, said: ‘Wow, it took some getting used to, but I’m fresher. I love it,’ ” said Rivers, the Celtics’ coach. “So there it is.”

For 38 years, the morning shoot-around has been an unquestioned staple of the N.B.A. game-day routine. It may soon be extinct, another dusty exhibit in basketball history, next to the peach basket, the two-handed set shot and John Stockton’s short shorts.