Mercedes have enjoyed a lot of success over the last four years by winning the Constructors’ Championship on each occasion.
Wolff’s team broke the Red Bull dominance between 2010 and 2013 where Sebastian Vettel drove home four consecutive championships.
However, Lewis Hamilton’s boss thinks that this year will be a much closer battle for the title.
Mercedes, Ferrari and Red Bull are expected to take it all the way to the wire and Wolff revealed his doubts about the upcoming campaign.
“We have a worst case and a best case,” Wolff told Sky Sports.
“What we have seen is that even if it is best case we are not in front by a lot, and if it is a worst case we are not far behind.”
Wolff’s comments came after he watched his drivers Valtteri Bottas and Hamilton fail to beat a time set by Ferrari on day one of the second testing session in Barcelona.
“What we have seen from Red Bull is that they have a very strong package,” Wolff added.
“I think will be very much in the game for race wins and the championship itself.
“I think it will be all three of us against each other.”