A strong Gunners line-up were beaten by the League Two Bantams 3-2 on penalties after extra-time ended 1-1, marking yet another negative result for manager Arsene Wenger this campaign.
Arsenal fans are starting to get fed up with the clubs lack of spending when they continually let top players leave with AST spokesman Tim Payton suggesting things need to change quickly at the Emirates Stadium.
"This is the most difficult time in Arsene's 16 years and both the club and himself need to change direction quickly if his wonderful era is not to end on a sad note," said Payton.
"The Arsenal Supporters' Trust cannot fathom why £70m was left untouched this summer.
"Arsene needs to get over his distaste for spending and use the resources that, after all, are provided by the hard-pressed fans who watch the team.
"The AST believe a shake-up is needed. We would like to see new, younger blood added to the board, and they also need to exercise more control and direction over Arsene's football strategy.
"One man cannot direct all transfer targets, wages, coaching methods and manage the team at games. It's too much for one man."