The Canaries welcome West Ham United to Carrow Road next Saturday, and the Scottish international said that the players must prove that they belong in the Premier League.
"It hurts - simple as that. It's humiliating," Sky Sports News quotes the 27-year-old as saying.
"We've let ourselves down and we've let the manager down. There is going to be a lot of soul-searching and conversation about this game, analysing it and going through it.
"We have got the characters in the dressing room. It is a good dressing room, a confident dressing room. We believe we are good enough to be in this league. Next week we will see what we are really made of."
The East Anglia-based club are 18th in the Premier League.