Rovers chairman John Ryan told BBC Radio Sheffield: "I'm disappointed. We will have to wait and see what happens.
"All we can do is make offers. It was certainly the biggest bid Doncaster Rovers have made for a player."
Asked whether Rovers would make another offer for the player, Ryan responded: "Not at this stage, no. I think we pushed the boat out a bit with that offer.
"It was a very substantial offer, so we'll have to regroup and see what happens with the rest of the summer."
Doncaster's current transfer record is the £300,000 they paid Manchester City for Matt Mills in 2008.
Sharp rejoined Sheffield United in 2007 from Scunthorpe for an undisclosed fee.
Source: BBC Sport
Source: BBC Sport