Cory Joseph has earned Patty Mills' playoff minutes

Though the Spurs still don't know what seed they'll be or who they're going to face in the opening round of the playoffs, most aspects of the team seem to be peaking at the right time and primed to do big things.

Tim Duncan's heating up, with back-to-back 20-plus scoring games and was named Western Conference Player of the Week for the 23rd time in his career.

Danny Green broke Chuck Person's franchise record for three-pointers in a season and has made 57-of-115 of them (49.6 percent) since March.

Kawhi Leonard is tearing up the league on both ends of the floor, leading the NBA in steals and shooting 57.3 percent from the field and 52.6 from downtown in April.

Tony Parker and Manu Ginobili both look less creaky than they did earlier in the season.

Boris Diaw is a legitimate post threat again.

Heck, even Aron Baynes is a post threat.

On the surface, it would appear that Tiago Splitter and his chronically edema-weakened calves are the team's only concern. Just about everyone knows what their roles and expectations are.

Except here we are, at Game 82, and the Spurs still haven't settled on their backup point guard. Since Dec. 28, when Patty Mills returned from rehabbing off-season rotator cuff surgery, he's played 791 minutes, to Cory Joseph's 708. Mills was given every chance to win the job in March so that the Spurs could return to the rotation they won the championship with, but he shot so poorly, 32.9 percent for the month, that Gregg Popovich had no choice but go back to Joseph in April.

If you go by the individual numbers, it's really no contest. Joseph is shooting 50.5 percent, to Mills' 37.2. He's even out-shooting him from deep, 36.4 percent (better than Leonard, Ginobili and Diaw as well) to 33.7 percent for Mills. Joseph gets far more rebounds, more assists, is four times as likely to block a shot and has almost identical steal and turnover rates to his Australian mate. He's bigger, stronger and the scrappier defender. Joseph has a 15.6 PER to Mills' 12.5, and his Win Shares Per 48 is .152 to Mills' .079.

The advance team metrics are even more damning for Mills. He has the worst net rating among the regulars, at -3.0, according to RealGM.com. It's actually closer to -4 according to my favorite stats database and yours, basketball-reference.com. Ironically, while Joseph has a slightly better defensive rating than Mills according to those sites, where he really pulls away is in offensive rating. It's 115.2 for Joseph to 101.6 for Mills. (I really have no idea what's up with NBA.com's numbers, where Mills is a defensive superstar.)

Perhaps the best way to look at Joseph and Mills is within the context of the teammates they're most likely to be playing with, and that's Ginobili, Diaw and Marco Belinelli.

Mills has gotten more of a chance with them, and has done quite well, according to NBAWowy.com, with a 100.8 offensive rating and a 89.4 defensive rating over 119 minutes together. That's a 11.4 net.

However, in 68 minutes together since Mills has been active, the quartet of Joseph, Ginobili, Diaw and Belinelli have managed an offensive rating of 112.4 and a vice-like 78.3 defensive rating, for a net of 34.1.

When put that way, it seems like a no-brainer. What sets Joseph apart from Mills is that he gives the second unit a secondary penetrator alongside Ginobili (or even a third one if they're out there with Leonard). That helps get opponents scrambling as the Spurs move the ball from side to side, and that's what opens up seams in the defense. Joseph's penetration was a key factor in the Spurs 16-4 run against the Suns on Sunday evening. Mills is active too and jets all around the perimeter, but he doesn't give you that drive-and-kick threat, let alone make layups.

Popovich wasn't too forthcoming when asked what roles he has in mind for Joseph and Mills, saying only, "They're backup point guards," and when pressed further, "Who plays depends on what I feel I need."

In that vein, it makes sense to turn to Joseph more often than not. He's the steadier of the two. With the Spurs starters figuring to control the stretches of games they're in there, all the reserves have to do is mind the store and not give up leads. Joseph, playing off Ginobili and Diaw, will do that. He's a superb mid-range shooter, a strong finisher, and he'll make people work to score.

Where you turn to Mills for then, is when you need a spark. When the team is lifeless and stagnant and nobody seems capable of hitting a shot. Sure, the odds are that Mills won't hit them either, but he's capable of getting hot at any moment and can score a bunch of points in a hurry. It's a desperation move, when you've got nothing to lose.

It seems familiar, somehow...

What if Mills helps the Spurs steal a game 6 on the road in the Western Conference Finals against the coach who did just that for San Antonio a dozen years ago?

No matter who Pop picks, two things seem certain.

One, the guy who's stuck on the bench will cheer his guts out whenever the one who's on the floor makes a play.

Two, Pop will probably change his mind another dozen times between now and June.