Goals from Jacob Murphy, Wes Hoolahan, Cameron Jerome and then Steven Naismith, saw Rovers go down 4-1 at Ewood Park.
The Rovers boss was pleased with the character shown by the players in the second half, with Anthony Stokes pulling a goal back, but the damage had already been done.
"It's not the start that any of us wanted, and not the start that any of us had envisaged either," Coyle told Radio Rovers.
"I thought we started the game quite well, I was pleased with the first ten minutes, but then the boy scores a wonder goal. But for us we should have got pressure on the ball before he is able shoot from 25-yards.
"But when you take that nosebleed you've got to stand up and be counted again and I felt for that ten minute period we were like rabbits in the headlights.
"Of course when that happens the confidence drains away from the players for conceding those goals.
"So for me the second half was about showing some character, showing that you are prepared to stand up and be counted and to try and effect things.
"We could have either felt sorry for ourselves or you pick yourselves up and show heart and courage, which for the most part of the second half I thought they did.
"Stokes, Byrne and Greer, the three subs, were probably our three best players on the day, but we can't take anything away from Norwich, they were outstanding.
"When all is said and done, as the manager I take full responsibility for that, we have to stand up and be counted, take it on the chin and make sure that we are better moving forward.
"We have to make sure that we are ready for every challenge that comes our way and learn the harsh lessons from today."
Rovers are back in action this Tuesday night when they travel to take on Mansfield Town in the first round of the EFL Cup.
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