Sheffield United are closing in on a £10million deal for Derby duo Jayden Bogle and Max Lowe.
Right-back Bogle, 20, and left-back Lowe, 23, were not in the squad as Derby beat Barrow on penalties in the first round of the Carabao Cup on Saturday.
Derby boss Phillip Cocu said Bogle had a minor injury but did not refute the idea they might be on their way out of Pride Park to generate funds to sign attacking players.
'If they leave I am expecting we will have the funds to strengthen,' said Cocu.
The Blades were in pre-season action Friday, playing out a 2-2 draw against Preston North End at Bramall Lane.
Chris Wilder's side will be among the last sides getting their Premier League campaign underway from next weekend when they host Wolverhampton Wanderers on Monday night.