The 24-year-old, who agreed to join the Canaries earlier in the season, has claimed that manager Chris Hughton has given him assurances that he will be the team's main striker.
"Some people may see my transfer as a step back," Sky Sports News quotes Van Wolfswinkel as saying. "But the Premier League is bigger than the Portuguese league. Life is good in Portugal, but the football has to be on a certain level too.
"Norwich is a small club compared to Sporting, but also a friendly club with a beautiful stadium and good fans. That suits me. The manager said I will be his number one striker. I know have to battle for it, but it's always good to get the confidence."
The Netherlands international has netted 38 goals in 50 appearances for Sporting.