Even before the Mavs signed Charlie Villenueva, Bernard James was (at best) the Mavs' fourth center, behind Tyson Chandler, Brandan Wright, and Greg Smith. And there are probably some who would rather have Ivan Johnson than Sarge.
Personally, I don't get that. Sarge is perfect for what he is. A cheap, popular emergency big, who hopefully never has to play, but gives you energy and grit when he does. Unfortunately, because the Mavs seem dead set on getting a stretch 4 on the roster (signing Charlie V to replace the previously signed, but lost to injury, Rashard Lewis), Sarge's days are numbered. He can't be traded until December, but the rumors are already starting up. However, let's say Sarge is still here in January and beyond; what will his role be?
Looking at Last Year
In 2013-2014, Sarge played in just 30 games and averaged just under 5 minutes per game. 0.9 ppg, 1.4 rpg, and 0.3 bpg are not exactly eye-popping numbers, but no one expected eye-popping from a second round pick who was already 27 years old when he was drafted. His per 36 numbers from last year are really pretty decent, especially for a 3rd center. Per 36 minutes, Sarge averaged 6.9 points and 10.4 blocks per game.
Still, Sarge's contributions to the team aren't really measured by stats. He served the same role he served his rookie year, filling in only if someone was injured or deep in Carlisle's doghouse. Unlike 2012-2013, last year's Mavs big men stayed mostly healthy, so Sarge wasn't needed as much. He did have one memorable night in Frisco, playing 37 minutes for the Legends while shooting 90%, scoring 38 points, nabbing 18 rebounds, and blocking 4 shots.
Best Case Scenario
Assuming Sarge sticks around, you can think about this two ways: best case for Sarge and best case for the Mavs. Best case for Sarge might be that one or more of the bigs in front of him on the depth chart get injured, and Sarge thus gets an opportunity to play in the rotation. He then proves that he has figured out the NBA game since last season, and proves he has the potential to be a legitimate backup center while playing something like 10 minutes a game.
Best case scenario for the Mavs is obviously that no one gets injured and everyone plays up to their ability. In this scenario, Sarge rides the pine the entire season and is never needed to step on the court. They always say that the best insurance plans are the ones you never have to use, right?
Worst Case Scenario
I think the worst case for Sarge and the Mavs is aligned. The worst possible outcome is that, due to a rash of injuries, Sarge is required to play big minutes and simply can't handle it. This would be particularly terrible if the injury was to starter Tyson Chandler. If the Mavs need to rely on Sarge for any significant stretch of time, and he can't provide something close to league-average center play, you can probably kiss the playoffs goodbye.
If Sarge is forced to play 10 minutes a game or more this season, for whatever reason, it will likely be a make or break year for him. If a larger role proves too much for him, it is unlikely any team is going to take a flyer on a 30-year-old emergency center who has never really done anything in the NBA.
One of the reasons that I'd like to see Sarge stick around for at least another season is that he is such a worthwhile presence in the DFW and Mavs community. And he has such a great story. By all reports he is a good guy and a good teammate. And because Sarge is making the minimum, he is an overall positive value for his role (both insurance plan and great guy) from a business perspective.
If Sarge does end up getting traded, I wish him nothing but the best. His time in the NBA may be limited, but I'm sure he'll continue to do great things in the future.