Peterborough chairman Darragh MacAnthony has slammed Grimsby for not selling captain Ryan Bennett.
Posh made two bids for the 19-year-old skipper of Grimsby, but both were rejected.
MacAnthony has now revealed that their second offer could have been worth up to £1million for Town - which he feels was more than enough to get Bennett.
"I am gutted at missing targets, but it wasn't for the want of trying," he told the Peterborough Evening Telegraph.
"We missed out on Bennett which annoyed me big time as we put together a deal that would have earned Grimsby up to a million over time.
"I am sure it would have allowed them to bring in four or five good players that may have given them a good push in League Two.
"I can appreciate when a club doesn't want to sell its best assets and that is fine if you are already competing at the top end of a league, but it may not be too prudent when you need to improve your squad."