During the regular season, Marco Belinelli made sure to earn his contract. During a season in which injuries ravaged the Spurs, he was extremely durable, ranking second in minutes played behind Tim Duncan. He was a dead-eye three point shooter all year long and he gave the Spurs a weapon they hadn't had in a while: a legitimate shooter off of screens. Imagining him as a legitimate difference-maker in the playoffs was always a stretch, but he was supposed to be an important cog for the second unit.
Unfortunately, Belinelli has been too much of a liability on defense to be a net positive for the Spurs. Even though his three point shooting percentage has remained above 40% for the post-season, his inability to play competent defense makes his significant rotation role hard to justify.
So it's understandable that after any Spurs loss, the option of benching Marco seems appealing, especially after a game in which he played over 20 minutes but had hardly any positive impact. If a guy hurts your team, the answer is to either reduce his minutes or find him a different role. Unfortunately, neither potential solution is that easy to apply, for a number of reasons.
It's impossible to play Manu and Marco together against the Heat
Belinelli has always been at his best when he shares the court with Ginobili. The two seem to share a brain and constantly find each other for open shots. In the regular season, Belinelli was much more effective with Ginobili next to him and even in his wretched playoffs, Marco scores more often and at a higher rate close to the basket when Manu is in. Playing him next to Manu is the easiest way of getting him going offensively. The problem comes at the other end.
Miami has had either Wade or James on the court for the vast majority of this series. Only the quirky rotations in Game 1 stopped them from always having one of them on the court at all times. That means Ginobili or Belinelli has to cover one of those two unless Lebron is playing power forward. Wade has taken advantage of those matchups and the Spurs have decided to try Diaw on Lebron instead of their smaller wings. As a result, Ginobili and Belinelli have been on the court for only 11 of Marco's 41 minutes. Pop understandably wants to avoid such obvious mismatches.
Without Manu, Marco becomes a far less dangerous offensive player. He turns into Gary Neal, a sniper who might hit a couple of shots but is not a threat to drive and either doesn't cut or doesn't get the ball when he does. The Spurs used to be able to pair Neal and Ginobili by playing Neal at point guard. That's not likely as it would mean cutting into Mills' minutes.
So if it's impossible to put Marco where he needs to be in to succeed often enough, then the Spurs should just hand his minutes to someone else. I'm not even going to entertain the notion of Austin Daye, mostly because I'm sure Pop won't. So that leaves two point guard lineups, with either Mills seeing his minutes extended or Cory Joseph taking Marco's place in the rotation. But there are pitfalls to that strategy too.
Mills can't defend and Joseph can't shoot
The Spurs tried the Mills-Parker back court for a small stretch in game one. The idea was to have Mills guard Ray Allen and take advantage of the fact that Allen is not an inside threat to get away with having a secondary ball handler on the floor. The Heat responded by running Allen through screens until a flare screen finally nailed Patty. Allen hit the open three. Mills countered with a long jumper but Pop had seen enough and sent in Marco after the next stoppage.
In Game 2, Pop learned his lesson and used the two point guard lineup with Parker on Allen and Mills on Mario Chalmers. It mostly worked because Wade attacked Belinelli, who was slotted at small forward, in almost every possession. With Wade isolating, Parker and Mills did fine. But if the Heat choose to move the ball instead, Parker would have to chase Allen around. The idea is to hide Parker on defense as often as possible, and playing him next to Patty makes that impossible.
So that leaves Cory Joseph. Having CoJo come off the bench for a couple of minutes to use his energy (and fouls) while trying to contain either Allen or Wade could definitely work. Wade is a fantastic post-up player and will likely score on Cory if Miami goes to him on the block. But exploiting that mismatch could take the Heat out of their normal sets, which could ice their role players. And if he has to guard Allen, Joseph is fast and feisty enough to chase him through screens.
The problem with playing Joseph is the Heat would help constantly off him when he is off the ball on offense. Miami could put Wade on him and have him roam near the rim. They could hide Allen on him. He won't even register for them on defense, especially when he is spotting up, since he has connected on a total of 23 three pointers on sub 30% shooting for his career. And the Spurs don't want to have Joseph handling the ball against pressure defense. At best, Miami will sag off of him and dare him to take mid-range jumpers. He can hit that shot but it would get the offense stuck in mud.
So there is no excellent option for replacing Marco's minutes and it's hard to have him on the court with Manu more. What can the Spurs do?
The other wings need to stay out of foul trouble
Belinelli is getting 20.5 minutes per game in the finals. That's way too many for a guy that has hurt the team. Why has he been on the court so much?
In Game 1, Marco was on the court for slightly over 18 minutes. That's pretty much the playing time he got in the other rounds, except for the Portland series in which he played well. It seems Pop's idea seems to be to have Belinelli on the court for about 15 minutes a game, which is fitting for a fourth wing. In all likelihood, Pop would have kept Marco's minutes even lower against the Heat in the first game of the series had it not been for the AC malfunction.
In game two, he played over 22 minutes because the Spurs needed a body. Ginobili had three fouls in the first half. Green had two quick ones in the first quarter. That's when Marco got most of his Game 2 minutes. In the second half, he logged only 8:04 minutes. That's the amount we can expect him to get.
As a 15-minute sub, Belinelli is decent. He won't kill you and he can always catch fire and hit a couple of threes. It's when his minutes are extended that he's exposed. And unless there is another technical difficulty in the arena or the other wings are in foul trouble, it's unlikely he gets a lot of time. No adjustment is necessary to reduce Marco's minutes as long as the rest of the wings to avoid foul trouble. If that means being more careful when setting screens or reaching in to avoid bad calls, so be it.
If everything is going well, Belinelli will likely play 10-15 minutes of the available 96 at the wing from here on out. And in that role, he can be an asset. So before doing anything drastic, it might be worth it to try and see how Marco handles the role he is supposed to have instead of the one into which circumstances have thrust him.