The fractured ankle of rookie guard Bill Nagy, combined with veteran Derrick Dockery still not seemingly ready to return from his leg/knee injury, is putting the Cowboys on search for some outside help at guard.
Nagy is expected to go to injured reserve this week, which will open the roster spot for another interior lineman.
With Tuesday being the regular day off for the Cowboys, it's often a time to look at other player for a possible workout. The Cowboys will likely bring in a few potential signees at guard, and don't rule out a player or two who has spent time with the Cowboys before.
The fact this team is looking outside, suggests it doesn't believe rookie David Arkin is ready for a starting role at guard, or even Kevin Kowalski, who was active for the game Sunday and filled in for Nagy on the final two drives.
One scenario could be to sign a center or use Kowalski there, and slide Costa to the left guard spot.
Either way, the Cowboys need some help on the line, particularly in the running game, which ranks 27th in the league, averaging just 69.6 yards a game. That will likely take another hit this week now that Felix Jones is out with a high-ankle sprain.
Rookie linebacker Bruce Carter is eligible to return from NFI (non-football injury) list this week, but the Cowboys won't have to immediately make a roster spot open for him. By league rules, Carter can practice with the team for two weeks before a decision has to be made to put him on the 53-man roster or injured reserve.
If Carter practices this week, but the Cowboys don't deem him ready enough to contribute against the Rams, even on special teams, then finding a roster spot for him right away wouldn't make sense.