The 34-year-old had made only three appearances from the bench in the league before his side's visit to Stamford Bridge.
"I was a bit surprised to be playing," said Carragher. "The Premier League is a step up, the Carling Cup and Europa League don't have the same intensity.
"It's frustrating [not to play] but I understand the stage of my career now and I'd never cause a problem here. I'm delighted to be involved and I'm here if the manager needs me."
Carragher is second in the club's all-time list of appearance makers, having played 711 times for the Reds.