Araujo was dismissed in the 29th minute for pulling down Bradley Barcola on the edge of the box with Barcelona leading 1-0 on the night and 4-2 on aggregate.
With Barcelona down to 10 men, PSG battled back and triumphed 4-1 at Montjuic, progressing 6-4 on aggregate.
Its a shame that the work of a whole season ends here because of a refereeing decision, Xavi told Movistar.
This dismissal is unnecessary.
Xavi was sent off for a show of dissent on the sideline as Barcelona lost their heads in the second half and he criticised Romanian referee Istvan Kovacs.
The referee was very bad, I told him, he didnt understand the game, said the coach.
Araujos red card led Xavi to take off 16-year-old winger Lamine Yamal, who created Barcelonas opening goal for Raphinha, with Inigo Martinez coming on to fill the hole in defence.
Were angry, the red card defines the tie, continued Xavi.
We were well organised, for me its too much to give a red card, from there its another tie.
Barcelona are eight points behind Real Madrid in the La Liga title race and face Los Blancos on Sunday at the Santiago Bernabeu.
Right now, thinking about Sundays game isnt the thing to do, said goalkeeper Marc-Andre ter Stegen.
We have to rest, charge our batteries and try to feel good again, above all mentally.
