Roar was defeated 3-1 by South Korean outfit Suwon Bluewings on Wednesday night, leaving its hopes of qualifying for the tournament's next stage hanging by a thread.
Despite an encouraging first half, Brisbane was far too lax in defence and Suwon capitalised on the massive space it was afforded, with a three-goal blitz at the start of the second half.
DeVere said Brisbane had no intention of straying from its possession-heavy style - but it would not work if players weren't focused.
"We know the way we play we'll always take risks," he said.
"We rely on players to be disciplined and to do their roles and, of late, we've lost our way a bit in terms of our individual jobs.
"If you look at some of the goals we've conceded, it comes down to some pretty simple mistakes.
"[But] we're not going to change the way we play; that's not something Brisbane Roar's looking to do."
Returning left-back Corey Brown had a dismal night in his first start for Roar since representing the Olyroos on international duty.
He turned over possession in a passage of play that eventually led to Suwon's opener, and was also partly at fault for its second and third goals.
Brown was a late inclusion for veteran Shane Stefanutto (calf), who pulled out after suffering an injury in the pre-match warm-up.
DeVere headed in Brisbane's goal in the second half to reduce the margin to two goals but the game was already over by that stage.
It was one of few clear-cut chances on the night for Roar, which must beat group leader Beijing Guoan in China and Japan's Urawa Red Diamonds on the Gold Coast to have any chance of remaining in the tournament.
Roar flew direct from Korea to Adelaide on Thursday ahead of its next A-League outing on Saturday at Coopers Stadium.
The fitness of Stefanutto and fellow defender James Donachie, who was taken off in the 65th minute with a hip complaint, will be assessed closer to the game.
Donachie's injury is understood to be not as bad as first thought and he is a chance of facing Adelaide United.
Brisbane will regain the services of in-form striker Jean Carlos Solorzano, who was not included in its Asian Champions League squad.
DeVere is adamant Brisbane has missed Solorzano on the continental stage: "If you look at the last A-League game against Central Coast, Nico had a fantastic game - potentially one of the best of the year for him," DeVere said.
