If under center, Rodger's left leg - the one in question - is his push-off leg. So just the act of dropping back will put some strain on the leg if it is weaker than advertised.
The real way to get to him is not target the leg for a hit, but make him run. Get him off his comfort spot and force him to avoid a pass rush. Make him find a soft spot outside of the pocket to launch his throws. Which means race to the spot to beat the defense there and have time to set up.
This, by far, will put more pressure on the leg to withstand the rigors of the game.
But the idea of targeting his leg in some act like we would see from Suh is despicable and has no place on this team, or perhaps even in this fan base.
More than hit him, make him run. Again and again.