The first significant NBA trade deadline domino to fall came over the weekend when the Mavericks acquired Caron Butler from the Wizards, completing a long-rumored exchange.

The Mavs did well in getting Butler and center Brendan Haywood (along with DeShawn Stevenson) for a package that included Josh Howard, Drew Gooden, Quinton Ross and James Singleton.

Butler and Howard essentially cancel each other out statistically if not stylistically, but Haywood is a significant upgrade over Gooden.

The move took one piece out of play for the Celtics, who had interest in Butler, but it certainly was not the only one.

Here’s what to watch for as Thursday’s deadline looms:

SCENARIO 1: THE RAY ALLEN MEGA-TRADE

This still looks like a longshot, but at least the market has been established from the C's perspective. If they are going to trade Allen, they want a talented young player in exchange.

Realistically, that means someone such as Kevin Martin, Andre Iguodala or maybe even Luol Deng, if the Bulls seriously do have his name out there.

The problem is that none of those teams have a compelling enough reason to give up their young stars for nothing more than an expiring contract, and that’s really all the Celtics have to offer.

Allen provides zero long-term gain for any potential trading partner, which is what Danny Ainge meant last week when he told The Big Show that the Celtics value him more than other teams do. Ainge still views Allen as a player who can help the Celtics win now and for the next few seasons if they can work out an equitable extension in the summer.

While a large expiring contract such as Allen’s brings short-term financial relief, it doesn’t provide any significant help on the court.

That’s a big reason why the Cavaliers are in on Amar’e Stoudemire. They can offer a big expiring deal like the one for Zydrunas Ilgauskus and they also have a young bargaining chip in forward J.J. Hickson.

There is no one like Hickson on the Celtics roster, and the closest match — Glen Davis — is what’s known as a base-year compensation player, which makes him tough to trade. (Go here for an in-depth definition of how this works.)

While there have been no indications that the Kings are even entertaining the idea, Martin still seems like the one to watch, and the Celtics coincidentally return to action Tuesday night in Sacramento.

If, and it is a big if, anything were to happen, the Celtics probably would have to take back Andres Nocioni, who has two more seasons left on his contract to make the math work. Or they would have to involve a third team with the requisite young big man the Kings are said to want.

That, once again, is the main issue with any deal involving Allen. The Celtics simply don’t have the additional piece to make it happen unless one of those teams gets desperate.

And that, once again, is why Allen is likely to stay.

SCENARIO 2: THE OTHER EXPIRING DEALS

Besides Allen the following players are in the final year of their deals: Brian Scalabrine, Eddie House, Tony Allen, Marquis Daniels, Shelden Williams and J.R. Giddens.

All together, they represent over $12 million in expiring contracts, and the Celtics could package a number of them to try to make a play for one of the lesser available talents. This is the secondary trade market that will open up late in the process once the bigger deals are either done or dead.

The Bulls are an interesting team to watch this week. Everyone knows they want to clear salary in an effort to open up cap space to make a run at Dwyane Wade and possibly a second free agent star this summer.

Kirk Hinrich and John Salmons are the key pieces to move with contracts that extend beyond this season, and the Bulls also would like to rid themselves of perpetual headache Tyrus Thomas. That’s where the original Allen-to-the-Bulls rumors started two weeks ago, but that’s not nearly enough of a return to justify trading him.   

It would take at least three expiring Celtics to get Hinrich and two to get someone such as Salmons. Presumably the Bulls would like to get something else of value back, but the markets for both players seem to be shrinking, and they may be forced to sell low.

Beyond that, it’s interesting to note the names that have cropped up over the last few weeks, particularly Charlotte’s D.J. Augustin and New York’s Nate Robinson. Both are offensive-minded point guards.

The Celtics have long had an issue at backup point guard, and while it’s true that Marquis Daniels can help in that capacity, the second unit does not have a player who can create his own shot and initiate the offense.

If they are going to make a move, it probably will be a tweak to the bench that alters the second unit’s on-court chemistry, and a player such as Augustin could do just that.  

TEAM TO WATCH: CLEVELAND

For the past few months, speculation has centered on the Cavaliers trying to acquire what is known as a “Stretch 4” (more commonly referred to as a big guy who shoots 3’s). They had been linked to Antawn Jamison with Indiana’s Troy Murphy as a Plan B, but not at the expense of Hickson.

Suddenly, Stoudemire has presented himself and of all the potential deals this one would be the NBA’s biggest game-changer, in more ways than one. 

Stoudemire is not a Stretch 4, but he is deadly on the pick and roll and could be an unstoppable combination in tandem with LeBron James.

But there are blinking red warning signs all around this deal. Stoudemire did not mesh well with Shaquille O’Neal in Phoenix last season. He also has never been known as a strong defensive player, and like the Celtics, the Cavs pride themselves on being a defensive-minded team.

That has led many to conclude that this is all an elaborate smokescreen designed to get Cleveland a better deal for someone such as Jamison and possibly get Philly back into the mix for a Stoudemire-Iguodala deal.

Either way, until this one resolves itself, all eyes are on Cleveland and Stoudemire.