The French forward made a slow start to life at Anfield but delivered a major response on Wednesday, scoring his first goals for Liverpool with a hat-trick in their 6-3 Champions League victory over LASK.
Iraola believes the reaction to Barcola's performances will continue to swing between praise and criticism as he adjusts to his new surroundings.
"Football is like this. You win a game, you are incredible; you have a bad performance, you are a disaster," Iraola said ahead of Saturday's Premier League trip to Brentford.
"It is going to be like this for Bradley, for everyone who works in football. We have to assume this."
The Liverpool boss believes regular football and a better understanding with his team-mates will help Barcola become more effective as he settles into the side.
"Now it is a matter of finding the best condition and best connection with team-mates, the level of understanding, the work of everyone, when to attack the spaces," Iraola explained.
"The more he plays with us, the more he plays with his team-mates, the better he will become."
Liverpool's progress has also been complicated by injuries, with Cody Gakpo, Alexander Isak and Dominik Szoboszlai all missing the last two matches after picking up problems while on international duty. The trio remain doubtful for the Brentford fixture.
Iraola also provided an update on centre-back Giovanni Leoni, whose return from a serious knee injury has been delayed.
The Italian suffered an anterior cruciate ligament injury on his Liverpool debut in September last year, but the damage extended beyond the ACL.
"Talking to the medical department, it wasn't just an ACL. It was a bad injury; a lot of things around the knee were involved apart from the ACL," Iraola said.
Leoni is now expected to begin the next stage of his recovery during the upcoming international break, slightly later than initially planned.
Liverpool will hope Barcola's Champions League breakthrough can provide a platform for consistent performances as they prepare for a demanding Premier League test against Brentford on Saturday.
