It could have been much simpler, these last years of Ray Allen’s Hall of Fame career, but simple isn’t always easy.

In nine days, Allen will take the court as a sworn enemy of the Boston Celtics. It will be the NBA’s biggest story on opening night. Boil everything else away — all the drama with Rajon Rondo; all the pride that makes us human — and you’re left with this: Allen took less money to play a similar role for the team that put the Celtics out of the playoffs in each of the past two seasons.

That’s legacy altering stuff. Rewrite the enshrinement speech and edit the obit.

There was a time, only a few months ago, when Allen could have had his jersey retired next to those of Bird and Russell and Cousy and all the rest. He helped Boston win its first NBA championship in 22 years. He set the NBA record for three-pointers in shamrock green.

There is a mystique to that shamrock. It’s stitched into the fabric of Boston like a badge of honor and it’s unlike anything else in basketball — maybe unlike anything else in American sports. To say otherwise, and to ignore that fact here, would be to ignore the very essence of this story’s significance.

Loyalty is to Boston as money is to New York, politics is to Chicago, the Rocky Mountains are to Denver and Hollywood is to Los Angeles.

Allen knew all this. Even before he played for Boston, even before he began his NBA career, Allen played college basketball at Connecticut for Jim Calhoun, a man born just outside of Quincy, Mass. Calhoun demanded fealty above all else.

Allen knew the price for leaving, and still he left.

In the end, it came down to this: What would that shamrock have meant to Allen if he had stayed? What would that jersey hanging in the rafters represent to Allen, the man, not Allen, the player?

These are the questions that motivated one of the greatest shooters ever to mortgage his meticulously crafted image as a New England institution, move his family to Miami and be the sixth man for the NBA’s defending champion, the almost-universally loathed Heat.

Allen could have made millions more in Boston and been respected not only as one of the organization’s greatest players but also as the player who sacrificed for the team. Some things inside the hearts of men, however, cannot be bought, reasoned with or ignored.

“I was very loyal to the city and I love the city, but when it came time to keep me in a uniform [the Celtics] did everything they could to seem like … to not want me to come back,” Allen said.

Yes, the Celtics offered Allen plenty of money to stay, but Allen viewed it as a hollow gesture. Boston signed Jason Terry in early July, ensuring that Allen would receive fewer minutes. He already had been benched for Avery Bradley. For Allen, who had helped restore Boston as an Eastern Conference power, it was too much.

Matter of respect

Allen is adamant that coming off bench for the Celtics ultimately had nothing to do with his decision to leave. After all, he’s currently coming off the bench for Heat, too. It was more about respect.

In the end, Allen didn’t feel appreciated in Boston. In his final two seasons there, he was made to feel old.

“In Boston, they were telling me they were going to bring me off the bench — ‘We’re going to play you less minutes’ — and all I asked was, ‘How are you going to use me because the last two years you’ve been using me as decoys,’ ” Allen said. “ ‘You’re running all these plays for me just to pass it to somewhere else and you’re not putting me into any scoring opportunities and I’m just standing over in the corner the majority of games.’ ”