Norwich City boss Paul Lambert has said he could not work out why his side were so lacklustre in their .
The Canaries made 11 changes to the side that in the Premier League on Sunday.
But Lambert was still able to put out a team containing regulars from last season's promotion campaign.
"It's disappointing but I can't put my finger on it," he told BBC Radio Norfolk.
"The team was very strong, a lot of them played last year and at the start of this season, we've been beaten by the better side.
"It's the first time in two years I've been disappointed with what's happened.
"The players know it wasn't acceptable and you expect a reaction come Saturday, you've got to respond to that.
"Nothing went right, absolutely nothing. I spoke to them after the game and said what I had to say."
Lambert's decision to overhaul his starting line-up would have been made with one eye on Norwich's trip to Chelsea in the Premier League on Saturday.
But the Scot has still ended up with two new injury concerns, with midfielder Wes Hoolahan coming off with a hamstring concern and defender Daniel Ayala injuring his knee.
"We'll have to see [on Hoolahan], I've not spoken to the physios yet, we'll have to see how he feels," he explained.
"I saw him stretching the hamstring, that's why I took him off.
"Daniel looks like he's hurt his knee, so we'll see how we are."