Moron, your bus is leaving.
Bonner should not be in the rotation. Bonner should get situational minutes and his shots per minute should be very high. He should be in at the end of every quarter and every situation where you want to draw up a play for a three pointer. It's amazing how having someone who does this will actually "spread the floor" for a change, so you can use him as a decoy since the opposing front line can't iso and feast on him.
He should not be the starting center, nor (and more importantly) should he be the center who ends the game. He should not be the backup center, he should not be the third string center. He should not have a position, he should have a role. Hence the term "role player". Popovich wants him to be Robert Horry, and has paid him accordingly. Doesn't change what he's not. Funny that the complete slapping the Grizzlies (and basically every front line) put on the Spurs isn't enough to open your eyes, but smarter people than you have failed to see reality.

"getting into a groove".