'Football isn't easy,' says Australia captain Ryan in response to critics
Australia's 4-0 win over 146th-ranked Indonesia drew only faint praise in home media while fans lamented the team's lack of fluidity in attack.
The victory came after coach Graham Arnold defended his squad's performance after an unconvincing 1-1 draw with Uzbekistan in the group stage.
Ryan said results were all that mattered.
"There can be a lot of outside noise and all that about, you know, the team should be doing this and doing that," he said.
"But you know football isn't easy... Everyone claims that it is from the outside. When you're out here and you're a professional footballer and you take on another team that's trying to do everything that they can to win a game, it's not easy.
"All due respect to Indonesia, they gave it a good crack."
Australia, the 2015 champions, will play either Saudi Arabia or South Korea in the quarter-finals.
Australia will hope to have forward Craig Goodwin ready to start after he came off the bench against Indonesia around the hour-mark, having missed the Uzbekistan game with a hamstring strain.
"I feel like we've still got a lot of improvement in us and I think that's a good sign going forward," said Ryan.
"We're a tight-knit group of boys. We all treat each other like brothers and it's like a family in here."