Cowboys promising rookie linebacker DeMarvion Overshown suffered a torn left ACL in Saturday night's preseason game in Seattle, Michael Gehlken of the Dallas Morning News reported Sunday.
The Cowboys feared that Overshown was dealing with a significant injury and an MRI done on the linebacker's knee Sunday confirmed the diagnosis.
"He's had an incredible camp. We talk about him almost every other day. I just hope he's okay," McCarthy said after Dallas' 22-14 loss. "He was climbing the charts. He showed up right away in the offseason program. You could see it when we got to Oxnard. His ability to fly around. He really has excellent command for a young linebacker."
Overshown was injured on the Seahawks' second offensive series when he tackled Seattle rookie running back Zach Charbonnet. Overshown grabbed his left knee and was tended to by the Cowboys' training staff on the field before walking off under his own power to the sideline and into the blue medical tent.
Overshown then walked over to a cart and was taken off the field and into the locker room for further evaluation. He was ruled out a short time later.
Overshown, a third-round pick in April's draft out of Texas, shined in the team's preseason opener and was expected to play a part in the team's linebacker rotation this season.
Undrafted free agent tight end John Stephens, who has been pushing for a roster spot thanks to a strong showing in camp, also suffered a torn ACL in Saturday's game, Gehlken reports.