With the draft in the rear view mirror, the focus now shifts to free agency, where the Spurs could undergo some dramatic transformations.

Seven players will enter free agency, including Tim Duncan and Manu Ginobili, who could decide to retire. The Spurs will surely retain Kawhi Leonard because they can match any offers he gets but Danny Green could decide to move on.

There's also the possibility that a big name free agent -- likely the Trail Blazers' LaMarcus Aldridge -- seriously considers joining the Spurs if they can carve out enough cap space to fit him in.

There are a lot of balls in the air right now and as soon as the July moratorium starts, chaos will reign. So before that happens, here's a free agency primer focusing on the possibility of adding a star to San Antonio's roster.

Salary Overview

All data from shamsports.com except the figure for Tony Parker, that is from Basketball-reference.com.

Now, a look at the projections for some numbers of interest.

2015-2016: Salary Cap: $67.1 million

2015-2016 Luxury Tax line: $81.6 million

2015-2016 2-year Veteran minimum: $947,276

2015-2016 Minimum salary: $525, 093

What are cap holds?

A cap hold is a placeholder salary used for players a team intends to bring back. For example, even though Danny Green will become a free agent on July 1, 150 percent of his previous salary will count against the cap for the Spurs unless they renounce Bird rights to him. This is done to prevent teams from using all the cap space available to them if just contracts were considered to bring in free agents and then going over the cap to bring their own players back.

The CBA requires that a team have cap holds for a minimum of 12 players. If the combined total of players under contract plus players whose cap holds are on the books is below 12, the cap hold for every open roster spot equals a rookie's minimum salary.

What's the most cap room the Spurs could have?

If they renounce everyone

If they renounce all of their free agents, including Kawhi Leonard and Tim Duncan, the Spurs could have around $33.5 million in cap space. That's not going to happen.

If they renounce everyone but Duncan, Ginobili, Leonard and Green

The Spurs wouldn't have any cap room. Cap holds for those four players would eat up all of their cap space. That's why the first thing the Spurs need to do is figure out what they are going to do with Duncan and Ginobili -- who will command lower salaries than their cap holds -- while waiting before re-signing Leonard and potentially Green, as those two will command a salary bigger than their cap holds.

Can the Spurs keep all four and add LaMarcus Aldridge?

It's possible but it would take complex cap gymnastics as well as sacrifices by some players. First, the Spurs need to get Tim's $15.5 million figure down. Mike Monroe reported that it is believed around the league that Tim will sign a 2-year deal with the first year in the $6-7 million range. Let's split that and use a figure of $6.5 million for Tim. Then the Spurs would have to convince Manu Ginobili to return for the room exception, worth $2.8 million. If they do that, they can renounce Bird rights to him and clear his cap hold.

With Duncan slotted to make $6.5 million, Manu completely off the books and cap holds for Green and Leonard accounted for, the Spurs would have $55.041,975 in committed salary, plus $2,100,372 in roster spot charges for a total of $57,142,347. That means they would have $10 million in cap space, a solid amount to add a free agent but only slightly more than half of what a max contract would pay Aldridge.

If the Spurs trade Tiago Splitter and don't take any salary back, they would have $49,167,440 on their books or $18 million in cap room. Again, a max salary for Aldridge starts at $18.9 million, so they are still short. It's possible but unlikely that Aldridge leaves money on the table to join the Spurs. So they would also have to trade someone else to fit him under the cap.

If they move Patty Mills without taking any salary back, they would have $46,113,586, giving them $21 million in cap space and finally allowing them to offer Aldridge a max contract.

As you see, it will be tight, which is why every penny counts, making the selection of Nikola Milutinov easy to explain.

Can the Spurs find takers for Splitter and Mills?

They should be able to with relative ease. In 2013 the Warriors were able to shed the $24 million they owed Richard Jefferson, Andris Biedrins and Brandon Rush by packaging them with two first round picks and multiple second round picks. Unlike those three, Mills and Splitter have value. Because teams know the Spurs have to trade them to carve out cap room, they won't likely receive assets back, but if the goal is to get them off the books, that should be possible to accomplish.

Should the Spurs renounce Danny Green and clear his cap hold?

If the Spurs sign Duncan to $6.5 million, renounce Ginobili only to bring him back for the room exception, keep Kawhi Leonard's cap hold in the books and renounce Danny Green, the math becomes easier. They would have $50,019,940 in committed salary and cap holds. They could then get down to $46,348,299 (enough room to offer Aldridge the max) just by trading Patty Mills and Kyle Anderson.

Doing that would give them a killer front line of Duncan, Aldridge, Splitter and Diaw but would leave them thin in the backcourt, with just Parker, Ginobili (or whoever they sign with the room exception) and Leonard. If they renounce Green and trade Splitter instead of Mills and Anderson, they would have $42,045,033 on the books. That's enough room to add Aldridge for the max while leaving four million in cap room and the room exception available to round out the roster.

It's much easier to carve out the necessary cap space without Green, who will become an unrestricted free agent anyway and could decide to leave. That's a tough decision the Spurs might need to consider.

What about a sign-and-trade or signing Aldridge for less than the max?

A sign-and-trade is technically possible but the Trail Blazers would have to be on board with the idea. In theory the Spurs could send out Splitter and Diaw for Aldridge, and then bring back all of their free agents. It's extremely unlikely that happens because if Aldridge leaves, the Blazers would be better served keeping their cap space to make an addition or go into a full youth movement. Fighting for a low seed makes little sense for them.

Aldridge signing for less than the max allowable is equally unlikely. Since the salary cap is about to explode, Aldridge might not want to sign for four years, preferring instead to re-enter free agency soon. That would mean signing a contract similar to LeBron James', which included an opt out after one season. James did get paid the max in that year in Cleveland, though, and Aldridge will almost surely want to do the same.

Teams and players rightfully look out for their own best interest first so it's hard to see how the Spurs get Aldridge any other way other than in free agency and for the max. As we've seen, doing that will require big sacrifices. Whether you believe they are worthy or not likely depends on your opinion of Aldridge.

Correction: This article originally stated that Aldridge was eligible for a max contract of $20.1M instead of $18.9M. h/t to longtime Pounder, Alamo, for pointing this out.