By Miles WrayIt can be tempting to think of the San Antonio Spurs as existing on a separate plane when it comes to making personnel decisions.This team saw potential in Danny Green after he played all of 115 career minutes for the Cleveland Cavaliers. This team looked at a then-overweight Boris Diaw, who had just been cut by literally the worst team of all time , and saw a championship contributor. This team, when forced to search out bargains this summer after giving out huge contracts to LaMarcus Aldridge and Kawhi Leonard, signed the 7’3” giant and instant fan favorite, Boban Marjanovic, for just $1.2 million.But the truth is, the Spurs still shuffle plenty of pedestrian players on and off of their roster. And they make flat-out mistakes, too -- the key being that they don’t make sizable commitment to players whom they are not absolutely convinced will perform. In recent years, players like Jimmer Fredette, Corey Maggette, and Eddy Curry have been with the Spurs in training camp. And in recent weeks, the Spurs cut two bench players from their 60-plus-win colossus in order to make room for two veterans who I also consider very unlikely additions to the team: Andre Miller and Kevin Martin.Unlike preseason auditioners, adding two players to the team this late in the season comes with a real price and little time to assimilate them. What’s more, the players the Spurs cut had been positive contributors to the team’s third unit (who receive plenty of playing time at the end of fourth-quarter blowouts). San Antonio acquired guard Ray McCallum via a trade with the Sacramento Kings last July in exchange for a second-round pick -- at the same time, Miller was floating on the free-agent market, and was picked up by the Minnesota Timberwolves weeks later. McCallum has since signed with the Memphis Grizzlies, meaning that he very well could face the Spurs in the playoffs. The wonderful resurgence of Rasual Butler’s career was also abruptly grounded: despite putting up career-best defensive numbers , he was released by the Spurs. To make matters worse, because Butler was released after March 1 (it happened on March 9), he is not eligible to play in this year’s playoffs, which is likely a huge reason why he has remained a free agent.In addition to giving up those two contributors, the Spurs received two veterans who, despite their significant offensive skills and lengthy career accomplishments, do not excel on the defensive end of the floor. Miller, who has just turned 40 years old since arriving in San Antonio, is definitely susceptible to opposing point guards sprinting straight by him. Here’s Miller (No. 24) struggling to contain McCallum (No. 5):After McCallum forces the switch on this pick-and-roll, Miller is clearly not on the same page as Tim Duncan, leaving rookie Jarell Martin (No. 10) open for the easy jumper:Seeing as Duncan may well be the very best defensive player in the game , I’m going to venture a guess that Miller is the player who misread there.Even though Martin has the better part of a decade on Miller (Martin is 33 years old), it feels like years of playing for offense-first teams in Sacramento, Houston, Oklahoma City, and even Minnesota have left Martin unused to being expected to play defense. While Martin is certainly giving it his best shot, he doesn’t have experience guarding his man with aggressiveness and physicality. Here’s 23-year-old Jeremy Lamb (No. 3) reading Martin (No. 23) like a book as Lamb curls around three screens to get free for the jumper:Here’s Lance Stephenson (No. 1) leveraging a screen and his speed to blow past Martin:And here’s Martin and Duncan on different pages with their pick-and-roll defense, leaving former Spur JaMychal Green (No. 0) open for the dunk:It should be acknowledged that both Miller and Martin have already made a number of subtly sublime offensive plays immediately after joining the Spurs. Miller has become famous as the years have gone on for continuing to play point guard at the NBA level despite his age. His continued presence in the league is proof that the ball really does move faster on the pass than on the dribble. Somehow, the 40-year-old Miller is able to make fast breaks work:Despite being hounded by a hungry McCallum here, Miller patiently breaks down the defense before directing the purposeful assist to Manu Ginobili. That’s some veteran chemistry:Even after he picks up his dribble, Miller has a remarkable ability to not panic within a broken possession as he searches for the best solution:At this stage in his career, Miller has moved past caring about stats more than just about any other player you’ll ever see. His usage rate this season is nearly half of his career average, as he’s only looking to take clearly open shots. By shooting over 60% from the field on the season, he’s having one of the most accurate seasons by a guard ever Martin has made all of his money in the NBA by being a premier scorer, making him a more-than-qualified floor spacer:What’s great about Martin’s arrival is he has begun contributing to those signature Spurs possessions of unstoppable cutting and ball movement:At the moment, Martin is receiving around 10 minutes a night in the Spurs’ rotation, while Miller has received 25 minutes and a start one night and a DNP-CD on another. When the playoffs arrive and rotations tighten up, I’d guess that Martin and Miller will spend most games on the bench, working as one the league’s most experienced insurance policies. For all their savvy and offensive creativity, though, I still don’t entirely see why the Spurs signed both players, as those defensive struggles can become liabilities in a hurry.