The Swans found themselves 3-0 down against in-form Canaries at the Liberty Stadium last weekend before eventually succumbing to a 4-3 loss.
That put an end to a six-match unbeaten run in the Premier League that included an eye-opening 2-0 win at Arsenal a fortnight ago and lifted them up to eighth.
Michael Laudrup’s team recovered from that blow to book a place in the semi-finals of the Capital One Cup by beating Middlesbrough on Wednesday and William knows this is an opponent we have to be wary of as we try to bounce back from our disappointing late loss at Everton.
“They play the best football and they are not scared to play,” said the defender. “It won’t be easy to beat them, even if they lost against Norwich.
“We have to be careful with how they play - quick, between the lines – and we’ll work hard on the training ground to be ready.
“We have to come back strong (after Everton), because this is a big game. It will be important for us to take the three points.”