Fuller was intended to part of the squad against Wolves before it was discovered his work permit only allowed him to play for Southampton.
Town Chief Executive Derek Bowden told the club website: "We are now waiting on when Work Permits UK will sit in judgement of the application.
"We are not sure if that will be immediately or not. Its just a case of waiting for them now and taking it from there, but the application has gone in."
Ricardo was drafted in on a one month loan as a replacement for the injured Alan Lee.