Northampton manager Chris Wilder has confirmed interest from Premier League and Championship clubs for Ivan Toney.
Notts County full-back Jordan Cranston has left the club by mutual consent.
Derby boss Nigel Clough has ruled out making a loan signing to help ease his central defensive problems.
Mark O'Brien and Jake Buxton face a race against time to be fit for Tuesday night's trip to Hull after suffering knee injuries against Sheffield Wednesday at the weekend.
O'Brien has been troubled by discomfort in his knee in recent weeks. He was named in the starting XI at Hillsborough but pulled out during the warm-up.
Clough turned to Buxton, who had not played in nine weeks due to knee ligament damage. He managed to get through the 90 minutes but tweaked the same knee that had kept him out.
James O'Connor, who can play anywhere along the back four, would usually come in and deputise but he is definitely out with a knee injury of his own.
Meanwhile, captain Shaun Barker will not play again until next season after undergoing reconstructive knee surgery in March last year.
"We've got centre-halves struggling and we are going to be a bit stretched, but we will find solutions from within the squad," Clough told reporters ahead of the trip to Hull.
"We will not go into the loan market for one game, as important as it is. I don't really see the benefit of that.
"All along we have said we will use the younger players if we have to and we will shuffle things around."