Nevertheless, Guardiola has always been open that the Norwegian will not play every match as City enter a frantic schedule with six games across 18 days.
He was coy on whether he would pick his striker against Forest, but did confirm if Haaland did not play, then Julian Alvarez would come in.
"When Erling doesn't play, we are going to play Julian. That is almost sure," he said.
"We are really impressed with his pace, his sense of goal, the work ethic, for many things.
"I knew him a little bit on TV and clips but I am surprised how good he is. He's so humble, always positive and every training session he gives everything. I like these type of players.
"The impact in the minutes he has played - he could have had a hat-trick at the Camp Nou and was involved in two goals in the last game - he has the sense of goals - we are delighted.
"I know people are talking about Erling and we are pleased but Julian is an exceptional player."
With the transfer window open for just another 48 hours, Guardiola does not know if any more business will be done, including a possible sale of Bernardo Silva.
"With Bernardo I have said many times how important he is for us," he added.
"Just one or two days until the transfer window is shut and everyone will be focused on what they have to do. I don't know what is going to happen."