Panthers RB Rashaad Penny retires at 28

(Photo credit: Bill Streicher-USA TODAY Sports)

Running back Rashaad Penny is calling it a career after six NFL seasons.

The Carolina Panthers placed Penny on the reserve/retired list Tuesday morning and signed undrafted rookie wide receiver Tayvion Robinson.

Tuesday's news comes on the heels of Penny recently declaring to the Charlotte Observer that he's one of the best running backs in the NFL when healthy.

Penny, 28