Ensign Sousa was played by recurring background actress Linda Harcharic, who received no credit for her appearances.
Sousa's name was not used on-screen, but was listed as a non-speaking role in the cast list of the script of "The Next Phase", but not specified beyond that in the script. This female conn officer is the only non-speaking ensign addressed in the episode.
As evidenced by the first draft script of "Relics", a male Starfleet ensign named Sousa was originally to have appeared at the conn of the Enterprise-D in that episode. However, her part in the installment was rewritten for Ensign Rager by the time the final draft of the script was issued.