<p> Carolina Panthers rookie running back Tyler Gaffney is out for the season with a knee injury.</p> <p> He'll undergo season-ending surgery on his left knee.</p> <p> Gaffney is a sixth-round draft pick from Stanford.</p> <p> “It’s disappointing because the young man’s a solid football player,” Panthers coach Ron Rivera said Saturday. “He’s had a history of being a workhorse, and unfortunately in practice (Friday) he got his knee in a bad position and something popped.”</p> <p> The Panthers plan to sign a running back.</p> <p> Gaffney rushed for 2,500 yards at Stanford. He rushed for 21 touchdowns as a senior.</p> <p> The Panthers cut cornerback De'Quan Menzie and signed defensive tackle Micanor Regis.</p> <p> Follow me on Twitter: <a href="http://www.twitter.com/RavensInsider">@RavensInsider</a></p> <p> Aaron Wilson covers the Ravens for The Baltimore Sun</p>