Chadwick scored twice as the npower League One leaders stunned the top flight new-boys, with further goals from Sam Baldock and substitute Daniel Powell making it a humiliating night for Paul Lambert's team.
"We knew they'd make some changes but Norwich have got a really strong squad and we knew whatever 11 they put out would be a strong team, so it's a great result for us," said Chadwick. "But I'm sure Norwich can do well in the Premier League. It's a wonderful club."
He added: "I enjoyed my time here despite all the injuries but they've got a good squad together, a big squad and there's such a great crowd.
"At the home games I'm sure they'll make it a great atmosphere and Norwich have every chance of doing well this season."
Chadwick was proud of the Dons' performance as they followed up Saturday's 6-2 drubbing of Chesterfield to reach the third round of the Carling Cup.
"It was a great night for the team. We've started the season really well but no-one expected us to come here and win 4-0 against a really great side like Norwich.
"Everyone's really happy but it's back to the bread and butter of the league on Saturday against Stevenage and that's going to be the most important thing."
He added: "They were well-taken goals. We like to pass the ball but we worked hard as well."
Source: PA
Source: PA