The shock 4-2 loss will see both teams into the hat for the Champions League round of 16 play-offs.
Arbeloa said afterwards: “Obviously, today we were far from what we wanted to be, given the difficulty of the match, the demands of our opponents, the atmosphere, what they were playing for, and what we were playing for. I don't think we were able to play 90 minutes at the level we needed to be."
On Benfica goalkeeper Anatoily Trubin scoring to give the hosts a 4-2 lead, Arbeloa continued: "It's not the first time a goalkeeper has scored against me. Obviously, they had to take a risk, we were playing with two players less and we also needed to score a goal to be in the top 8. They took a risk, we took a risk and in the end they won."
On his interaction with Benfica coach Jose Mourinho at the end, Arbeloa appreciated the Portuguese's words at the end.
"I was not surprised at all. I said it yesterday in this press room and in the different interviews I gave, that the demands of the game were going to be very high. I was fully aware of the level of the opposition, the atmosphere and the coach that was going to be in front of us.
"I told the players but obviously I didn't know how to transmit to them what I wanted them to do on the pitch. When things don't work out, when the team is far from the level we gave, for example, in Villarreal, the responsibility is always and absolutely mine because I didn't know how to get the players to face the game in the way I wanted them to. And the rest is between me and José."
He added, "I am responsible for the defeat, just as I was in Albacete. I don't know if you've been to those two press conferences, but I said it and I'll say it again: I feel totally responsible when things don't go well and we don't achieve the objective we had.
"It's not that we have been eliminated from the Champions League. We have two games ahead of us and with the objective of going through to the next round, we are going to face it."