DALLAS -- The two point guards the Dallas Mavericks acquired in blockbuster trades since the end of last season sat next to each other on the bench during crunch time Friday night.

It's certainly no surprise to see Raymond Felton, the tax in the Tyson Chandler trade, riding pine with the game on the line. But it's rather alarming to see Rajon Rondo sitting with his warm-ups on and a towel over his head for the final 5:12 when his teammates are trying -- and failing -- to pull out a hard-fought win over the Chicago Bulls.

After all, owner Mark Cuban and coach Rick Carlisle often rave about Rondo's proven clutch prowess after Dallas' nearly-two-year pursuit of the four-time All-Star finally ended in a deal being consummated with the Boston Celtics in mid-December. The Mavs coveted Rondo because he reminded them so much of Jason Kidd, a savvy point guard who consistently rose to the moment in crunch time.

So why the heck was Rondo a highly-paid courtside spectator when it mattered most against the Bulls?

"Coach's decision," Carlisle said after the 102-98 loss at the American Airlines Center.

Good, then we're asking the right guy. What was the logic behind that decision?

"A decision that the coach makes," Carlisle said, and that little dance went on for a few more questions, making for some entertaining sound bites but revealing nothing.

That, of course, leaves the door wide open for speculation. Kind of like opponents often leave Rondo, a notoriously poor shooter, wide open on the perimeter.

And that leads directly to the most plausible theory for not playing Rondo down the stretch against the Bulls.

The Mavs were in comeback mode, trailing by eight points, when Carlisle decided to replace Rondo with Devin Harris. Shooting and floor spacing were at a premium in that situation, and Harris is a much more effective 3-point threat.

Would it be wise for Carlisle to say that for public consumption? Of course not.

Just ask former Mavs coach Avery Johnson. That was the reason he provided after benching Kidd for the final 34 seconds of a loss to the San Antonio Spurs soon after the Mavs made a blockbuster trade for a former All-Star point guard in 2008. That certainly didn’t go over well in the locker room or work out long term for Johnson, who was fired after the Mavs' first-round exit that season.

Let's be clear here: That's where the comparisons to that Kidd crunch-time benching and Rondo riding pine with Friday's game on the line should end.

There isn't any friction brewing behind the scenes between Carlisle and Rondo, who made a point to say he appreciates what his coach has done for him during their brief time together and attempted to downplay the issue.

"Life is too short to complain about not playing five minutes of a big game," said Rondo, noting that he has the maturity to handle these sort of situations now, unlike when he bumped heads with Doc Rivers early in his career with the Celtics. "Like I said, I'm a competitor. I'm pretty sure you guys know that I wanted to be in the game, but it didn't happen. I did my best to cheer my teammates on."

Of course, benching Kidd seven years ago was a factually flawed decision. By that point of his career, Kidd had become a pretty good 3-point shooter, better than Jerry Stackhouse, whom Johnson put on the floor instead of Kidd in that crunch-time situation in San Antonio.

Rondo, with his funky form, is still at least a summer's work away from being even a mediocre 3-point shooter. Many cited Rondo's poor shooting -- 25.9 percent from long range for his career -- as reason for concern about his fit within the Mavs' high-powered flow offense when the trade was made.

The Mavs' offensive efficiency has slipped from sky-high before the trade to pretty good since Rondo's arrival. Their defensive efficiency has improved dramatically, addressing a glaring need for the Mavs, but Rondo didn't have a great night on that end, either, as evidenced by Bulls point guard Derrick Rose's 20 points, 18 of which were scored in the first half.

So a case can be made that Carlisle made the right decision, especially considering that Rondo wasn't effective in his 26 minutes, finishing with 6 points on 3-of-9 shooting, 4 assists, 2 rebounds and 2 turnovers.

However, it directly contradicts his comments after Rondo played a key role in the Mavs' 14-4 run to close out the Memphis Grizzlies on Monday, when he struggled most of the game before sparking the critical spurt with a floater and baseline jumper. ("A guy like that, you've just got to put him in there in crunch time and let him do what he does," Carlisle said then.)

It can also easily be argued that the best rebounding guard in basketball shouldn't have been watching from the bench on the final possession. Rondo couldn't do anything to prevent Rose from grabbing the offensive rebound with 4.7 seconds remaining that essentially sealed Chicago's victory, forcing the Mavs to foul.

If Rondo had been in the game on that possession, the odds of Carlisle getting the opportunity to draw up a potential game-tying or winning play for the dynamic, clutch scoring duo of Monta Ellis and Dirk Nowitzki would have dramatically increased.

This actually isn't the first time Rondo has been a crunch-time spectator for the Mavs. He sat the final 51.2 seconds of the Mavs' 108-104 overtime win over the Sacramento Kings on Jan. 13 despite making an improbable stepback 3 with 1:14 remaining to give Dallas the lead for good.

Carlisle explained that by saying Rondo had a sore Achilles tendon. The Mavs cited that ailment when Rondo sat out the next night's loss against the Denver Nuggets, but that didn't stop some skeptics from being suspicious that the Mavs feared the Kings intentionally fouling the point guard, who is shooting 30.2 from the free throw line this season.

If Rondo's shooting is indeed the reason for Carlisle sitting him down the stretch, it presents some other questions. Two pop to mind.

Is this going to be a somewhat regular thing? We'll find out as the season goes on.

If so, how much is Rondo really worth to the Mavs? We'll find out this summer when it's time to talk money with the pending free agent.