Isn't anybody a hated rival anymore?

After a 107-76 regular-season loss to LeBron James and the Cleveland Cavaliers in 2009, Ray Allen sounded like the last guy who'd ever want to play with King James.

Allen witnessed James and then-teammates Delonte West and Mo Williams do everything but the dougie to celebrate their rout on the sideline.

"I'm always going to remember that," a surly Allen said after the game. "If I beat a team, as happy as I may be in victory, I'm always going to stay humble. … We play each other too much. Those are just great motivational thoughts for me."

With Allen joining James and the Miami Heat on Wednesday -- the first day NBA teams can officially sign free agents -- maybe he and James can work on performing the Cupid shuffle.

Just two weeks ago, 38-year-old Steve Nash said there was no way he would ever join the Los Angeles Lakers, whose star Kobe Bryant revealed in January how much he disliked Nash's Phoenix Suns.

"The truth is I am a bit old-school," Nash told ESPN radio in New York. "I think for me it would hard to put on a Lakers jersey. That's just what it is. You play against them so many times in the playoffs, and I just use them as an example with the utmost respect for them and their organization."

Also happening Wednesday: Nash's sign-and-trade to the Lakers will be completed.

It's a strange NBA world. Thirty-five is the new 25, and rivalries among players and teams seem to be as shallow as a Kim Kardashian marriage.

I don't begrudge Nash or Allen the right to find new teams. They were free agents who could go anywhere they chose.

But did they really have to join these two teams?

This is the ripple effect created by James and Chris Bosh going to South Beach and winning a NBA championship. Players and teams seem panicked to put together squads with multiple star players, because the fear is that the Heat are poised to make good on LeBron's promise of multiple championships.

It's creating some seriously strange bedfellows. Some are theorizing that part of the reason the Cavs were reportedly one of four teams involved in Dwight Howard-to-the-Nets discussions is because Cleveland owner Dan Gilbert still wants revenge on LeBron. Supposedly Gilbert was helping to create a formidable championship roadblock to the Heat in Brooklyn since he didn't back up his insane declaration that the Cavs would win a championship before LeBron.

Hard to believe, but stranger things have happened -- like Allen in a Heat uniform.

In Allen's case, joining Miami was a better alternative than losing to the Heat the remainder of his career, assuming he stayed with the Celtics. In Miami, Allen isn't expected to log starter minutes, but one can imagine he'll get a plethora of wide-open shots created by James and Dwyane Wade slashing to the basket.

Going to Miami made perfect basketball sense. But what of previous bitter memories? What happened to the old-school rule of redoubling efforts to defeat that team ahead of you, showing some pride, not giving up and joining a team just because it seemed unbeatable?

Forget about the implications of trading a two-time MVP in the same division and helping a hated rival fill its biggest void.

The new unofficial rule is that everybody should create a version of the big three -- perhaps even a big four in L.A. -- to stop the Heat.

I'm disappointed in Nash. As the only multiple MVP winner who has never been to the NBA Finals, it looks like he swallowed his pride to chase a ring. Before the trade to the Lakers, Nash swore the absence of a championship or even going to the Finals wouldn't define his career.

Maybe not.

Allen didn't owe the Celtics, who tried to trade him this season, but he owed the process. Yes, the Celtics have lost to Miami in the playoffs for two consecutive seasons, but can't some of that be attributed to bad luck? Rajon Rondo, with whom Allen reportedly had a fractured relationship, was hurt in the Miami series in 2011. This year, Avery Bradley, the Celtics' best perimeter defender, was out with a shoulder injury. With the addition of Jason Terry, the Celtics could conceivably be the one team strong enough to stand in the Heat's way in 2013.

Certainly we've seen star players merge with rivals before. Dennis Rodman helped Michael Jordan win three NBA titles after Rodman had won two with the Detroit Pistons, helping to pummel a younger Jordan along the way. And championship teams always have multiple weapons, though not all of those weapons are created equal.

But I don't know if I'm comfortable with such cozy collaborations among supposedly irreconcilable foes becoming the norm in the NBA. If a player could so easily jump to a team that just beat him in the Eastern Conference finals -- even if part of the motivation was sticking it to the team that tried to trade him -- that doesn't say much about the state of player and team rivalries in this league.

In-season rivalries haven't blocked career decisions in some time, but can you blame me for being pollyannaish and wishing that they still did?