Steve Bruce is hopeful Benjani will be joining the club after Sunderland's last-gasp move for the Manchester City striker.
Speaking before Monday night's ESPN game with Stoke Bruce said his club had got all the paperwork off on time and were awaiting confirmation.
The 31-year-old Zimbabwean had been in talks with Blackburn but now his fate rests with the Premier League.
When asked if Benjani would be heading to the Stadium of Light Bruce said: "We hope so, we have done everything properly. It was very, very late but we hope it's been accepted by the FA.
"It was pretty hectic at five to five when everything was going in there. At this moment in time I'm not so sure but Niall Quinn the chairman is very, very confident that it has been completed."
Bruce also said he hoped Kenwyne Jones would hit top form again after his proposed move to Liverpool failed to materialise.
He said: "I think it's been unfortunate. there's been no offer from anyone for Kenwyne Jones. I think I've made it public about the Liverpool thing with a loan deal being bridged and obviously it's turned the boy's head a bit.
"My big aim is to get him turned round a bit and to be the Sunderland centre forward like we know he can be. He's a fantastic player and a good boy."
Bruce, after his team's dour 0-0 draw with Stoke City, blamed technical difficulties for any hold-up in the registration but remains hopeful.
"I think we've lodged everything in time, we've done everything we possibly can and I'm convinced we had everything in in time.
"The paperwork was lodged but we had some huge, huge difficulties and we informed both the Premier League and the FA at the time of those.
"It was well in front of the deadline when we got the green light to get Benjani in on loan but we had huge, huge difficulties with email and faxes so we hope a little common sense prevails.
"We wait to find out but I hope we are granted the player, who would be a huge boost to us."