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 have rejected another bid for highly-rated defender Jason Shackell.
Burnley have been heavily linked with Shackell, who had an impressive first season for the Rams in the Championship after joining from Barnsley last summer, captaining the team in the absence of injured Shaun Barker.
Derby chief executive Tom Glick told the Derby Telegraph: "We've knocked back another bid for Jason Shackell.
"We felt it was nowhere near where it would need to be for us to give it serious consideration.
"We're not surprised about this as he had a great season for us and is a key player for us, in a key position.
"If a club was to come back with an increased valuation, we would take a look at it on its merit.
"Then, if we felt it did meet out valuation of the player, we would only sell if we had a suitable replacement lined up."