The running back joined the NFC North side from the Miami Dolphins earlier this year.
The wide receiver told NFL Radio: "I knew [Bush] was a good running back, I knew he could catch the ball out of the backfield, but when he motions and gets into the slot or goes outside and runs a route.
"He didn't look like a running back running a route, he looked like a receiver running a route. And that's a really big difference and for people who know football, they know exactly what I'm talking about."
Bush rushed for 986 yards for the Dolphins last season, scoring six touchdowns.