Ange Postecoglou promised Nottingham Forest fans they will see his attacking style in place within days, despite starting his tenure with a 3-0 defeat at Arsenal.

The Australian, appointed on Tuesday after Nuno Espirito Santo’s dismissal, had limited time to prepare but insisted there were “small seeds” of progress in his first game.

Forest were largely second best at the Emirates, struggling to trouble Arsenal before conceding a decisive second goal early in the second half.

Postecoglou, who endured a turbulent exit from Tottenham last season despite delivering the Europa League, said he would waste no time reshaping Forest’s approach.

“No, mate, it won’t be months, it won’t be weeks, it’ll be Wednesday,” he said, targeting immediate change in the midweek League Cup tie against Swansea City.

“This is not a project,” he added. “This football club had a strong season last year and needs to be stronger this year. My job is to get us to where I want us as quickly as possible.”

Forest face six matches before the next international break, giving Postecoglou little margin to embed his trademark aggressive football.