The Cottagers have failed to pick up a single point after their poor start to the season, being beaten by Ipswich Town, Millwall and Wolverhampton Wanderers.
Magath told BBC Radio 94.9: "I'm convinced that we can manage [promotion] this season.
"Sure the fans are not satisfied with the situation, but we have to change things and Fulham is not just struggling at the moment, they have been struggling for the last couple of years. The fans know that."
Magath, 60, will take his Fulham side to Derby County on Saturday as they aim to pick up their first points of the Championship season.