'Los Blancos' supporters handed the tickets back due to concerns over the lack of accommodation in Kiev and travel problems.
UEFA ruled that the returned tickets could be reissued by Real to fans who missed out in the original ballot. However, fears remain that hundreds will remain unsold.
Cost of accommodation has been a constant problem leading up to the final, with numerous Kiev residents stepping in to offer their free sofas to travelling supporters.
In addition, stadium prices have soared. One seat in a corner of the Olympic Stadium, with a face value of £281, is advertised for almost £15,000 whilst some VIP packages will cost over £20,000.
James McKenna, spokeman for Liverpool fan group 'Spirit of Shankly', expressed his disgust to the 'Times'.
He said: "If there are any empty seats at the final in Kiev it should be a wake-up call for UEFA. It should be a wake-up call for them anyway.
"This has been a debacle and it is down to the choices made by UEFA about the location of the final and the ticket prices.
"If you are a Real Madrid fan being offered one of these returned tickets for €300 (£263) to €400 (£351), with no possibility now of flying to Kiev and hugely expensive accommodation — if there is any — then you can understand why they might say 'No thanks'."