The Dallas Cowboys have signed rookie free-agent defensive end Toby Jackson and released defensive tackle Ikponmwosa Igbinosun.
The moves Wednesday are part of a revolving door on the defensive line as the Cowboys await the return of Anthony Spencer and Jay Ratliff and deal with a season-ending Achilles tendon tear for Tyrone Crawford.
Jackson was among four players who worked out for Dallas on Tuesday. He wasn't selected in the NFL's supplemental draft after being declared academically ineligible for his final season at Central Florida.
Igbinosun was in camp with Pittsburgh last year after signing as an undrafted free agent. The Cowboys picked up him at the end of last season, but he was hurt during the first week of camp.