Karanka took the loss on the chin and hopes that Boro's performance at Anfield will energise their fans into inspiring the Teesside club into building on their promising start to the Championship season.
"It's football," he told reporters. "The most important thing for me is that I have to tell them 'thank you'. They were brilliant, our crowd were brilliant, everything was brilliant apart from the last penalty. Hopefully now our crowd are excited about this season again.
"I was speaking with the players before extra-time, I was speaking with the players – with Patrick Bamford and Jelle Vossen before they came onto the pitch – and we were going to have one chance to score one goal.
"We scored the goal and we got the penalties, but we lost. We have another game on Saturday to look forward to."
Middlesbrough are currently fifth in the Championship, having collected 15 points from eight games this campaign.