The Dutch striker is in very good form for Real Madrid and scored the winner against Real Betis on Saturday.
“I form part of the team and Do my job. We have all started well and we have shown that we never give up,” he told AS.
“It is a good time to go to Russia, but it is going to be a difficult game and we will have to work hard in Saint Petersburg.
“Zenit are doing well and it will be as difficult as the game against Betis was.”