Billy Davies is hoping for a quick resolution to Benny Feilhaber's £1m move to the Rams.
The 22-year-old has agreed terms and passed a medical on a three-year transfer from German side SV Hamburg.
But the deal can't be totally completed until international clearance is received for the USA midfielder.
"Benny has finished off his medical and trained this morning, when he looked excellent," Davies said.
"We are hoping now to get the clearance done as quickly as possible."
Feilhaber penned his deal before Tuesday's 12noon cut-off point, which would make him eligible to feature in Wednesday's game at Manchester City - if international clearance is received in time.
Derby need to get the relevant paperwork by 5pm on Wednesday if they are to include him at the City of Manchester Stadium.
And discussions are still ongoing regarding Finnish international midfielder Mika Vayrynen.
The 25-year-old has agreed terms on a move from PSV Eindhoven but has picked up a slight niggle.
"Mika has gone back to Finland as he is carrying a slight calf injury so discussions are still ongoing," Davies said.
"We are hoping to get him back over the next week or so to finish off one or two things."