"Maybe Red Bull might (win) in Monaco," he said, "because that circuit is not about power."
Lewis Hamilton, however, who has won the last four grands prix on the trot, warned that the W05 will once again be difficult to beat even on the tight, twisty streets, where even the main 'straight' is not straight.
"Things should close up as there are not really many straights, so hopefully we'll see a much closer race," he said.
"Red Bull have a very good downforce package and McLaren should be good there as well," added Hamilton, "but we're still going to be quick there."
Teammate Nico Rosberg agrees: "Red Bull keeps raising the bar and even Ferrari is not far away. They are trying as hard as they can to close the gap," he told DPA news agency.
"But I am optimistic that we can stay ahead."
It is therefore likely that, once again, the main spotlight of interest will fall on the battle between Hamilton and Rosberg, who is desperate to fight back after four consecutive defeats.
"I just need that extra little bit, then I'll be back at the front," the German driver said.
"I'm convinced that it's my turn now," Rosberg smiled.
Mika Hakkinen, the 1998 and 1999 world champion, also said it is too early to write Rosberg off.
"Actually Nico doesn't need to do much differently," the Finn told Hermes.
"He just needs to continue to build on his strengths and eliminate the weaknesses, and it could be different already in Monaco.
"Nico is always very good on street circuits," Hakkinen added.