Internal growth is as important as free agency for the Spurs

With so much to digest this offseason -- including whether Manu Ginobili or Tim Duncan will retire and who the Spurs will try to sign -- the  growth of the current personnel has been almost an afterthought. Yet it became increasingly clear during these past playoffs that the Spurs still depend far too much on the production of the Big Three.

As Tony Parker struggled, the starting unit ceased to function; If Manu wasn't productive, the overall bench play suffered; Tim Duncan essentially carried the Spurs in game seven.

As awesome as Big Fun is, there are fundamental issues with having a 39 year old lead your team in almost every statistical category in the most important game of the season, especially in a year in which the transition to younger players was supposed to take place.

That's why the most important aspect of this offseason is going to be internal development, as signing a star can only help so much if the current players stagnate in their growth or take a step back. As always when discussing the Spurs' future, the first name that comes to mind is Kawhi Leonard but there's another X factor under contract who could also make a leap.

Kawhi Leonard needs to understand what it means to be a star

After Kawhi's huge game three, it appeared he had finally turned the corner into becoming the leading force on the roster. Especially after mediocre showings in games one and two, this standout performance was supposed to be the spark that lit the Kawhi-era fire. Unfortunately, it turned out to be an outlier.

Bill Simmons recently brought up on a "Bill Don't Lie" podcast the fact that Leonard -- and I am paraphrasing here --didn't seem to trust his own talent yet, that the one thing holding him back was himself. I tend to agree with that assessment and that obviously has to change. This is the offseason in which Leonard has to tell himself "this is my team. I am the best player on the floor right now" for the Spurs to have a chance to win the title next year. Like other up and coming stars, Kawhi has the talent to be a top five player in the league, but it is up to him to get there.

Of course Leonard doesn't just need to work on changing his mindset. He got his first taste of double teams against the Clippers. It might have been the first time he saw them consistently but it won't be the last. Coming into 2015, he will be the defense's main focus night in and night out. He has to be ready to accept that role and work on the aspects of his game that will allow him to be a factor even when the other team game plans to stop him. Being aggressive when he does get to go one-on-one and making the right passes when he faces an extra defender are at the top of his list.

Luckily for both him and the Spurs, heading into this offseason, Kawhi is healthy. There aren't any lingering injuries and he will have an extended time period to improve his game and get rest. Kawhi has never had this long of an offseason being a prominent member of the San Antonio Spurs. He's known for his outstanding work ethic so it's exciting to imagine what he can do with five months off.

The Spurs need a reliable Patty Mills

There aren't a lot of players currently under contract as it stands now, which makes the few that are particularly important. The one veteran who is and could still realistically improve after a rough season of dealing with injuries is Patty Mills. Unlike Kawhi, that improvement isn't necessarily tied to developing new skills but finding the consistency the Spurs need from Tony Parker's backup going forward.

During the regular season, Tony Parker was able to experience plenty of rest thanks to the emergence of Cory Joseph as an excellent and steady backup point guard. With so many other players to retain, the likelihood of Joseph staying in San Antonio could be smaller than fans would like to imagine. Naturally, Patty Mills is going to be looked to fill in that role now that he's healthy, as he did in the playoffs.

Mills needs to be able to find a way to consistently maximize his talents. His impact is made clear in the numbers as he owned the highest plus/minus of any Spur during the postseason. If he can be the player he was in the playoffs 80 percent of the time over the regular season, any potential drop off in Parker's production should be easily masked by Mills' three-point fueled offense and pesky defense.

For Patty to do that, he will need to come into training camp in shape. He's battled with weight issues in the past and the worst thing that could happen would be for him to become complacent if Joseph leaves and he finds himself without competition for minutes. A healthy, in shape Mills had a breakout season in 2013 and could make another leap in 2015.

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The bottom line is that this Spurs team has maybe one more year of the Big Three. It's imperative for the pieces around them to be the best they can be because Parker, Ginobili and Duncan can't do it on their own anymore. Hopefully that improvement also transforms the current talent into pieces that can lead the Spurs into a new era of success.