This.Can't really stop Garza. But if you can harass Bohannon, you can disrupt Iowa's offense. He's the guy who really makes that team go on the offensive side.
The Smarmy McCaffery is good at feeding the post, but he doesn't do much else on the offensive side of the ball. Bohannon directs traffic from outside the arc and when defenses screw up on the PnR, he (usually) knocks down open jumpers. Don't double Garza off him, don't even sag off of him. Tell BU what flavor of gum he's chewing by halftime.