The Cowboys worked out three veteran free agent offensive linemen on Thursday and given the pace at which their depth chart has been thinned by injuries, Montrae Holland, Derrick Dockery and Daniel Loper might be sticking around Oxnard, Calif., this weekend. Right guard Mackenzy Bernadeau (hip) and backup center Kevin Kowalski (ankle) are the one physically unable to perform list. Left guard Nate Livings (hamstring) sat out Friday and backup center Bill Nagy (ankle) joined the group because he sprained his right ankle; Nagy fractured the same ankle in October 2011 against the Patriots. Dockery and Holland were with the Cowboys in 2011. Holland started 10 games for the Cowboys last season but finished the season on injured reserve. Dockery suffered a fractured tibia and sprained MCL and started only two of nine games with the Cowboys last season. He has 113 career starts in nine seasons.