With Junior Paulo on NSW Origin duty and Reagan Campbell-Gillard, Shaun Lane and Ryan Matterson injured, the Eels this week signed Ofahengaue from Wests Tigers but he suffered a calf injury just 10 minutes into his club debut.
Hooker Reed Mahoney and forwards Isaiah Papali'i, Marata Niukore, Oregon Kaufusi and Nathan Brown have all joined rival clubs.
With Ofahengaue injured, Wiremu Greig was forced to play 47 minutes in just his 14th NRL appearance and he led the Eels forward pack as the home side withstood a late Cowboys fightback, sparked by fullback Scott Drinkwater.