The Spanish giants went down to a Didier Drogba strike in the semi-final first leg at Stamford Bridge last week, despite dominating possession.
Feyenoord boss Koeman, who won the European Cup with Barca in 1992, said that he would "never" let his side play like Chelsea did against the Spaniards.
"I watched Chelsea defend for 90 minutes and I was appalled they did not try to make something more of the game. I have no admiration for Chelsea's approach," The Mirror quotes him as saying.
"And, let's face it, this tie could have been all over by now. Barcelona could easily have won in London.
"Let's hope football will be the winner this week and the team with the best approach goes to the final.
"It is the moment when a team like Chelsea have the chance to create something and they won't which annoys me. As a team, you can't sit back and wait for Barcelona all the time."
Former Manchester United keeper Edwin van der Sar echoed his compatriot's sentiments, saying that he hopes Chelsea lose the return leg "for the sake of the game and for football in general."
He added: "I love teams who attack. Chelsea did nothing but defend with nine players and kept lots of players in the middle of the park. But this tie could have been over by now.
"I expected Chelsea to lose by a big figure. And it could still have been 5-1 to Barca at the end. Chelsea had just one shot at goal - and they scored."
The return leg will take place at the Nou Camp next Tuesday, April 24.