Dallas signed Demercado to its 53-man roster Tuesday, Tommy Yarrish of the Cowboys' official site reports.
The Cowboys waived Demercado ahead of their Week 5 contest versus the Buccaneers, but he's now back with the club as it prepares for Week 6. As long as starter Javonte Williams and Tyler Goodson remain available, Demercado projects to be used only sparingly, if at all.