Rangers manager Steven Gerrard is said to have made several bids to bring Cooper to Ibrox.
Some Millwall fans are beginning to fear the worst after Glasgow Rangers' interest in Jake Cooper reportedly developed into multiple bids from the Ibrox side.
The Daily Mail claims Rangers are now close to meeting Cooper's release clause, having submitted an offer worth £3 million for the Millwall defender.
And while many Millwall fans were initially confident about keeping one of last season's star men - a few even demanding up to eight figures for Cooper - doubts appear to be creeping in.
This is what they are saying on Twitter...
That's him gone then we never turn down that sort of money but still spend nothing !— David Embleton (@dbe281061) 11 July 2018
I still think he will go. But I would want a least double that for him.— T-Biscuit (@amastukel) 10 July 2018
The writing was on the wall with Millwall when they signed Murray Wallace. You will regret letting Cooper go for peanuts. Had 60 years of this as a Millwall supporter. Just say NO !!!!— John H Rower (@JohnHal72196066) 10 July 2018
If it's a straight cash deal then it's good business.— Matt Webber (@s61_mjw) 10 July 2018
What’s Jake Cooper’s release clause?! Surely we haven’t been this stupid again?!— ShonkieBiz (@ShonkieBiz) 11 July 2018
Should Cooper leave for Rangers, he would become Steven Gerrard's third central defensive recruit since taking over in May.
Connor Goldson and Nikola Katic have already arrived at Ibrox, where David Bates and Russell Martin have departed since the end of last season, with Bruno Alves and Fabio Cardoso likely to follow.
Will Millwall lose Cooper to Rangers?