Replacing Vince Carter and Shawn Marion on the new-look Mavericks

There are lots of reasons to be optimistic about the Mavericks coming into the season -- not only did they give the Spurs their toughest challenge of the playoffs, they brought back Tyson Chandler and added Chandler Parsons in free agency. After three years of fighting for the No. 8 seed, many projections have them in the running for home court in the first round. If there's reason for concern, it's the two pieces they lost -- Shawn Marion and Vince Carter.

Both guys are over the age of 35 and well into the downswing of their careers, but they still brought a lot to the table last season. Not only were they among the most respected guys in the Mavs' locker room, they were two of the team's better athletes and the only two-way players on last year's roster. Vince and Marion plugged a lot of holes in the rotation and for all the talent the team brought in, there aren't any obvious replacements for them.

Shawn Marion

While Marion's defensive numbers have been in a gradual decline over the last few seasons, he was still the team's main perimeter stopper, matching up with four different positions and covering for Dirk, Monta and Jose Calderon. He was the guy who got the main assignment on Tony Parker in last year's playoffs and his ability to bottle up Parker and force him to take contested jumpers was one of the main reasons why the Mavs were so competitive.

His on-court/off-court numbers don't totally reflect the value he brought to the team, since he was the Mavs primary backup power forward and spent a lot of time on the floor without Dirk. One of their best lineups last season came when Dirk and Brandan Wright would play together and blow second-unit frontcourts off the floor. That only worked because Dirk took a rest early in the first and third quarters, forcing Marion to play as a small-ball power forward.

Marion had career-low offensive numbers last season, one of the primary reasons why Dallas was looking for an upgrade at the small forward position this off-season. At the same time, he was still a productive player, averaging 10.4 points, 6.5 rebounds and 1.4 assists on 48 percenet shooting. He even started knocking down threes again, shooting 36 percent on 2.1 attempts a game. He knew how to play without the ball and put up points without having any plays run for him.

In five seasons with the Mavs, Marion never courted the spotlight or put up huge offensive numbers, so his contributions flew a little under the radar. He guarded four positions on defense, swung between two positions on offense, put up numbers without demanding the ball and never killed the team's spacing. There are not many guys in the NBA who can come close to replicating his skill-set and the Mavs will look a lot different without him.

Parsons is replacing him in the starting line-up, but they are much different players. He will improve the offense but he isn't nearly the rebounder and he's only an average defender at the small forward position -- he's going to have a hard time playing too many minutes as a small-ball power forward and he won't be able to guard many point guards or shooting guards. The other perimeter players are going to have to carry more weight on defense and match up with the best players at their position.

Al-Farouq Aminu provides a lot of the same defensive versatility and rebounding as Marion, but he can't hit the broad side of the barn and he doesn't make a lot of good decisions with the basketball in his hands. Aminu shot 27 percent on 0.6 threes a game last season -- Carlisle will have a hard time keeping him on the floor with a center while maintaining the team's floor spacing. It's unclear how he will fit into the rotation, especially with how unsettled the bench is.

Vince Carter

Vince had a pretty good case for Sixth Man of the Year last season, when he averaged 12 points, 3.5 rebounds and 2.5 assists a game on 41 percent shooting. He did a little bit of everything on the second unit -- he was their best perimeter defender, their best shot creator, one of their best playmakers and he was also an above-average shooter and rebounder. Even at 37, he didn't have any real holes in his skill-set and he always found a way to make a positive impact on the game.

Mavs fans had a love-hate relationship with Vince because of his often questionable shot selection, but a large part of that was a function of his role with the team. There were not many other places the Mavs could look for offense off their bench, particularly when Devin Harris was out. None of their frontcourt reserves could create their own shot and you couldn't count on guys like Jae Crowder and Gal Mekel with the shot clock winding down.

If Vince had the ball in his hands, he could always create a shot for himself or someone else. He could take guys off the bounce, he could use his size to go into the post and he could run a pick-and-roll. At 6'6 220 with a 6'11 wingspan, Vince still had a physical edge on a lot of the second-unit guys he was facing and he could match up with first-unit guys at either wing position. There's a reason Vince closed out so many games in his time in Dallas.

He turned back the clock in the playoffs -- not only did he hit one of the greatest shots in franchise history, he absolutely tore up the Spurs defense, averaging 17 points a game on 46% shooting per-36 minutes. He had 28 points in Game 5 and he had four games with a +/- higher than +9. With Vince no longer in the picture, a lot of guys on the second unit will have to assume more responsibility and the Mavs are smaller and less athletic at the wing positions.

Looking forward

That's my main concern when I look at how this team will replace Vince and the Matrix -- all of a sudden, the Mavs are very small on the perimeter. None of their top four guards -- Jameer Nelson, Raymond Felton, Monta Ellis or Devin Harris -- are above 6'3 and it's hard to know what you are going to get from Aminu and Richard Jefferson at the backup small forward. They are going to need a lot from Jae Crowder, a guy who didn't have to do much playing next to Vince.

Dallas is going to have a lot of trouble matching up with bigger wings, which is not a position you want to be weak at on defense. Parsons is going to have his hands full dealing with the other team's small forward - there's no one on hand who can match up with big shooting guards, guys like James Harden, Arron Afflalo, Wesley Matthews, Klay Thompson, Manu Ginobili and Goran Dragic. That could be a huge problem in a seven-game series, which always comes down to matchups.

Even if the Mavs had more wing defenders on hand, there are not many guys who can handle that responsibility while improving your offense as well. There's a reason Vince is in Memphis and Marion is in Cleveland -- these are guys who can still play big roles on elite teams in their late 30s. They are players with legitimate cases for the Hall of Fame and they were two of the most respected guys in the locker room.

The Mavericks will miss them.