Nottingham Forest head coach Ange Postecoglou says he "cannot afford to waste time" as he seeks to implement a new style of play at the club.
The Australian's first game in charge ended in an emphatic defeat with a 3-0 loss away at Arsenal.
The 60-year-old was appointed as Nuno Espirito Santo's successor on Wednesday and vowed to build a side in his image.
While there was evidence of stylistic changes against Arsenal, Forest managed just one shot on target against the Gunners and registered a lower expected goals (xG) than in any game Premier League match under Nuno.
Asked how long it will take until we see a Forest side playing in his image, Postecoglou said: "Wednesday mate (against Swansea). I can't afford to waste time, this is not a project.
"I'm not going to let it take long, we've got an unbelievable opportunity to make an impact."
Martin Zubimendi, a £50m summer signing from Real Sociedad, scored either side of an effort from Sweden striker Viktor Gyokeres to move Arsenal to the top of the table.
The loss leaves Forest on four points after four matches this term, though midfielder Elliot Anderson was keen to point out the positives.