"We (fans) are always the forgotten people in this but it's nothing new," said Garreth Cummins, a Liverpool fan and international officer at the Football Supporters Federation.
"I can't remember a single time when UEFA have made a decision and thought about the fans or at least overtly made some consideration to them," he told Reuters.
European football's governing body UEFA said on Monday that the Europa League semi-final first legs involving the two English clubs would go ahead despite travel chaos caused by the widespread closure of airports across the continent due to a cloud of volcanic ash.
Fulham said they would be travelling by land for Thursday's match at Hamburg SV.
While Liverpool players were due to take the train to London and on to Paris for an overnight stay before heading to Bordeaux and a flight to Madrid for Thursday's game at Atletico Madrid, their ticket-holding followers were less fortunate.
"I can see UEFA's point that if they were to postpone this game it might be helpful to Liverpool fans perhaps but it would then inconvenience Atletico fans who were due to come over next week (for the second leg)," added Cummins.
"The main problem was they waited until yesterday to announce (the game was on). It just doesn't give us any time to make new travel arrangements or to drive down."
Cummins said Liverpool had been allocated 2,500 tickets for the match and a "significant majority" - between 1,500 and 2,000 - had been sold.
"Everyone I have spoken to has all but given up hope of getting out there," he added.
"It certainly won't be four figures. I'd be impressed if even 500 make it out there."
Liverpool manager Rafa Benitez expressed concern for the supporters after his team beat Premier League strugglers West Ham United 3-0 at Anfield on Monday night.
"The people working on the travel plans for us have been very good," he told reporters.
"But all the fans, maybe they can't go and that's a pity. We have fantastic fans behind the team when we go away but I'm disappointed they might not be there."
