Dallas Cowboys offensive guard Nate Livings needs to have another surgery on his right knee, according to ESPN Dallas.
Livings underwent knee surgery in February.
He got hurt again in May, but was unable to practice Thursday.
The Cowboys are also without guard Mackenzy Bernadeau due to a hamstring injury.
So, the Cowboys have signed Jeff Olson and James Nelson as reinforcements for the line.
The Cowboys are also looking at former Kansas City Chiefs and New England Patriots offensive guard Brian Waters.
Follow me on Twitter: @RavensInsider
Aaron Wlson covers the Ravens for The Baltimore Sun.
Check out our partners at TiqIQ for the best deals on all games on the 2014 NFL schedule.
NOV 26 Joel Corry
Elvis Dumervil will be handsomely rewarded after his big night in New Orleans.
NOV 25 Jeff Fedotin
Tampa Bay wide receiver has a TD in four straight games.
NOV 20 Joel Corry
A detailed look at the eight candidates vying for that unique honor.