I'm curious. Why can't you say the same thing about Omri? I thing Casspi is the ultimate team player; he's hungry and eager to earn a spot on the starting roster but he's not going to cry about it if he is outplayed for the position.
I think our team chemistry right now is better than it's been in a very long time. If anything, the competition between guys for minutes is going to push them to get better. And from everything I've seen about Casspi, he's a tough competitor. If it makes both he and Donte work hard, all the better.
Personally, I think the whole "starter" thing is over-rated, which I've said before. The Spurs have done pretty well with a system that allows for flexibility in some starting positions to take advantage of matchups, etc. I could easily see Westphal utilizing that kind of system to good advantage, especially with the young talent he has available.
You may think it's over rated, but from the player's perspective, financially speaking, it's not. It means more minutes (in general, Ginobli is a rare case), more exposure, more endorsement contracts, a bigger contract down the road. From the player's perspective, it's huge. One of them will eventually win and settle into that starter spot, and the other may become discontent at being 6th or 7th man. However, if they are still playing a prominent role, and we are making deep playoff / championship runs, they may not pout, but as soon as we start losing or slipping, you can bet they'll want out, they may not say so, but they will, and with good reason, too, I believe.
You simply can't just ask these guys to give up trying to get a major contract for the sake of the 'team', but you can provide a winning environment that would make them rather play on a winner, for possibly less money, for possibly a lesser role than they'd play on a losing team, if.... we are close to winning a ring. That really would be the only thing that would make it worth it, for them, for their careers, their families etc. And I believe rightly so.
You can't always put the "malcontent" label on the player. For example, I don't think any of us really blames Noc for wanting out. We didn't LIKE his attitude, but I think we could all understand.