Nov 6, 2014; Portland, OR, USA; Dallas Mavericks guard Jameer Nelson (14) looks over at the bench during the third quarter of the game against the Portland Trail Blazers at the Moda Center at the Rose Quarter. Mandatory Credit: Steve Dykes-USA TODAY Sports

The Dallas Mavericks knew times would be rough while fielding an entirely new roster.

They were probably hoping Jameer Nelson would play somewhat close to the All-Star level he was at in Orlando. As of this moment, Nelson has been the biggest disappointment for the Mavericks not related to a third quarter.

This was supposed to be the ideal situation for Nelson. He leaves the young Orlando Magic for a contender in Dallas, and now in his 10th year in the league, had a chance to show he still had some game left in him.

Even though Dallas is not even a quarter of the way done with this season, it’s time to start rethinking if Nelson is the point guard Dallas can trust.

It’s not because Nelson can’t play the position. He’s shown he can. But there’s no flow to the offense with Nelson running the point. More times than none, the ball just sticks. It’s just iso basketball, with Nelson at the top of the key and hope something good happens.

Check out this play from Thursday’s game against the Portland Trail Blazers, and keep an eye on the shot clock.

Nelson only hands the ball off once during that possession, and he turns into Monta Ellis on this play. Instead of giving it to Dirk Nowitzki, who has Damian Lillard on him after the pick, he takes the tough shot with LaMarcus Aldridge right in his face.

Those kinds of shots are not ones a point guard should be taking. The argument can be made that Jose Calderon did the same thing last year. While that may be somewhat true, the difference is Calderon was a better 3-point shooter than Nelson. Calderon was also better shooting off a pick-and-roll than Nelson is.

Nelson hasn’t had to play in an offense where he’s come off a screen and is taking 16-foot jumpers. That wasn’t his game in Orlando. His role in Orlando the last couple of years post Dwight Howard, as it should be now, is the catch-and-shoot variety.

And if you thought that one was bad, this one might have just topped the cake.

There’s 14 seconds left on the shot clock. You have plenty of time to set up a play, direct the offense and get a better shot. Instead, Nelson thinks the ball is burning his hands and has to get it off with 10 seconds left on the clock. That led to a Robin Lopez putback at the other end, and the snowball kept rolling.

This isn’t to say Nelson is the root of Dallas’ problems, especially in the third quarter. But it’s decisions like these that show the Mavericks are panicking in the third quarter. Portland was on a little bit of a run, tied the game and eventually took the lead.

You just don’t rush a shot like that. That was bad play by a point guard. Emphasis on ‘a point guard.’

It wasn’t even Thursday’s game against Portland that was the problem. This has been going on for the entire start of this season.

If this keeps up, Rick Carlisle needs to make some changes. The problem is, it’s a known fact that he prefers Devin Harris off the bench, and he’s done very well in that role.

But when does Carlisle look at the numbers, and see three assists per game is not good for a point guard?

Meanwhile, Harris has averaged 4.8 assists per game off the bench in only one more minute of play than Nelson.

So if Carlisle feels keeping Harris on the bench is a good idea, then you only have two other options: Raymond Felton or J.J. Barea. Any option sounds better than a point guard shooting 34 percent from the floor.

Going into this season, Nelson was on a short leash with the abundance of depth Dallas has at point guard. It’s only a matter of time before we find out how short that leash really is.

For Dallas’ sake, it better be pretty short.