Ray McCallum has big shoes to fill

The San Antonio Spurs made a trade to shore up their point guard depth after the departure of Cory Joseph in free agency. Their target was Ray McCallum, a former second round pick who couldn't find a permanent role with the Sacramento Kings.

On the surface, it was the perfect move for a team trying to win now. McCallum plays hard, has some experience and is still young enough to improve. Digging a little on his performance so far into his young career, however, shows that the 24-year-old is more of a question mark than someone ready to step in and contribute right off the bat.

McCallum tries hard on defense but doesn't make a positive impact

Trying hard is a requirement on defense, especially at the point guard position. The smallest players on the floor get screened constantly and are always trying to either put pressure on the ball handler or recover after not being able to stay in from of their assignment.

McCallum doesn't take plays off and has been described as a defensive-minded player by coaches but that's clearly not enough for him to be an asset on defense. When McCallum has been on the court, his team has hemorrhaged points, even after he became a starter late in February.

The Kings were always better on defense with McCallum off the court, no matter his role. Of course his teammates could have had something to do with that but every individual stat also paints McCallum as a subpar defender. Defensive Real Plus Minus has him ranked 448 out of 474 players and opponents shot 5.3 percent better when he was guarding them than on average, per SportVU data.

Both the eye test and Synergy Sports data suggests his biggest problems are navigating screens and containing drives in isolation. Poor communication with the bigs can be blamed for his inability to anticipate picks but he doesn't seem to have the strength to fight through them or the quickness and length to recover.

Getting completely crushed by screens and playing one of the league's most notorious non-shooter so close are big mistakes. Typically it's the little things that kill McCallum, like taking too long a route around a screen or simply not being in an athletic stance at all times.

McCallum is just 24 years old and has been in the NBA only two seasons without a clear role. He could definitely improve with time and coaching. Expecting him to be as effective as Cory Joseph was at times as a defender against starters, however, just doesn't seem realistic at this point.

McCallum doesn't do anything particularly well on offense

It was often frustrating to see Joseph not even look at the rim despite being wide open beyond the arc, opting instead to put the ball on the floor. The results, however, were mostly good, as he got to the basket and the free throw line at a decent pace by venturing to the paint often instead of futilely trying to be a three-point threat. It severely limited his versatility as an offensive player but at least made him an efficient one.

McCallum, on the other hand, still hasn't figured out what his strengths are. He certainly has the tools to be a solid offensive player but he hasn't found a way to use them effectively yet. At this point, there are not many areas in which he can be considered even above average.

*Among rotation point guards, according to ESPN.

His three-point shot wasn't good in college but it fell in his rookie season. He took very few attempts (85 between the NBA and his stint in the D-League) but shot 37 percent, which is solid for a point guard. Then last season, likely as a result of that past success, more of his total field goal attempts came from beyond the arc but his conversion percentage plummeted down to 30 percent.

He fared better as a dribble driver after struggling greatly his rookie season. In shots he finished in the restricted area after at least two dribbles his percentage went up from a measly 46 percent to a decent 52.7 percent. He's still nowhere near elite as a finisher (for comparison, on a down year Tony Parker shot 55 percent under those circumstances) and he doesn't draw enough fouls, but it was a step in the right direction. Now he needs to up the frequency with which he drives.

McCallum averaged just 5.8 drives per 36 minutes last season. For comparison, Joseph drove over eight times per game and Parker over 12 times. Point guards who don't have a three-pointer need to get to the lane as often as possible, something the former King doesn't do. That reticence to go to the rim aggressively combines with a shaky mid-range game that features too many off balance shots when the path to the basket is closed to make McCallum a mediocre offensive player.

McCallum might be more of a project than originally thought

After the trade that brought McCallum along, a popular opinion was that he was a perfect replacement for Cory Joseph. He was the same age, their stats looked remarkably similar and he had just filled in for a team that had lost its starter and had done so well. The comparison was almost inevitable.

Alas, it looks like McCallum might not be as far along in his development at Joseph was. That's not ideal but also not a big problem for the Spurs. They still have him under contract for cheap this season and the next and he's young enough to continue to grow as a player. It's even possible that in a new environment he flourishes and does live up to the expectations many had when his arrival was announced. The potential is there.

Assuming he will be as good as Joseph or near his level from day one, however, would be setting him up to fail.