(REUTERS) - Lewis Hamilton's grid penalty may be the break Nico Rosberg needs to re-ignite his Formula One title bid but the German is refusing to take victory in Sunday's Belgian Grand Prix for granted.
"That is going to make the weekend less difficult for me, for sure, because he is my biggest direct rival," Rosberg told reporters at Spa on Thursday.
"Nevertheless it's still going to be a challenge."
Hamilton, who leads Mercedes team-mate Rosberg by 19 points in the championship, will start from near the back of the grid after being penalised for exceeding his permitted allocation of engine components.
That would appear to leave the way clear for Rosberg on Sunday but he does not expect it to be straightforward especially as Red Bull are now strong enough to capitalise on the smallest opportunity.
Hamilton, in the form of his life, could also charge through the field with the 7km Spa circuit offering plenty of overtaking opportunities.
"If we remember four weeks ago I finished behind two Red Bulls," said Rosberg, referring to the last race in Germany where he started from pole but ended up fourth.
"I still need to beat all the opposition and Lewis, always need to reckon with him because with a bit of luck and safety cars at the right moment there is no reason why he can't come from far back and through the grid."
Rosberg led Hamilton by 43 points following May's Spanish Grand Prix but has since steadily lost ground to the Briton who has blitzed his way to six wins from seven races.