Citing a report on Pro Football Talk, who had the Cowboys with $7.2 million in cap space as of last last week, Ellis suggests that the Cowboys will have around $4 million in cap space remaining after the signing of first-round cornerback Morris Claiborne. With Claiborne slotted to count nearly $3 million against the cap ($2.957 million, to be exact), basic math leads to the $4 million cap figure.
Because only the Top 51 contracts count against the salary cap before the regular season begins, Dallas will actually have closer to $5 million in cap space after signing Claiborne. When Claiborne signs his contract, his $2.957 million cap figure will bump an existing contract out of the Top 51. As of right now, that player is kicker Dan Bailey, who has a cap number of $465,833 for the 2012 season.
Ellis is right that the Cowboys should have plenty of room to sign a veteran free agent. At this point in the offseason, most unsigned veterans are inking deals that contain little to no guaranteed money and, via the "Minimum Salary Benefit", count less against the salary cap.
Additional cap room could be cleared by signing franchised linebacker Anthony Spencer to a multi-year extension before July 16. Spencer currently counts $8.856 million against the team's cap.
A "Cowboys Cap Fun Fact" (that may actually interest no one): According to my roster and salary cap database, Morris Claiborne's anticipated $2.957 million cap number would rank ninth among current Cowboys' contracts. The two players directly ahead of him on the list would be fellow cornerbacks Brandon Carr ($3.2 million) and Orlando Scandrick ($2.98 million). Disgruntled Cowboys cornerback Mike Jenkins ($1.672 million) is outside of the team's Top 20 cap figures for 2012.