The 25-year-old missed the club's pre-season tour due to the injury that occurred after a collision with goalkeeper Declan Rudd in training.
"Thankfully there was no cartilage damage. It was bone bruising and a slight strain in his calf," Norwich boss Neil Adams told BBC Radio Norfolk.
"We've been told 10 days to two weeks for Ricky."
The Canaries signed van Wolfswinkel last summer as the club's record signing for around £8.5m.
Norwich were relegated from the Premier League last season after recording just 33 points, van Wolfswinkel scored just one goal for the club.