Celtic defender Kolo Toure has accepted the blame for his side's 2-0 Champions League loss to Borussia Monchengladbach on Wednesday.
Toure, 35, was at fault for both of Gladbach's goals to leave Celtic bottom of Group C on one point after three matches played.
"In that kind of competition you can't afford that kind of mistake. I have to blame myself," Toure told BT Sport, in quotes reported by the Daily Mirror.
"I have to blame myself because it was a simple action to put the ball to the side. I like to play and give my team the ball but maybe not there.
"It was the same with the second goal. I'm 35-years-old and still making 16-year-old's mistakes."
Celtic manager Brendan Rodgers said of Toure: "He is a guy who is very mentally tough and he will recover.
"I thought the best team won, I don't think there is any argument about that. My players gave absolutely everything but they were up against a top side.
"Our only disappointment is the two goals -- they didn't create so much even though they looked dangerous on the counter attack which a lot of the German sides will.
"We gifted them two goals really. We had some good spells as well but we were beaten by a side who are very good, technically strong, fast, with good power and who have quality. We have no complaints."
With Group C leaders Barcelona and Manchester City still to play, as well as a trip to Gladbach, even a Europa League spot looks a tough task for Celtic.
"It is very difficult of course," Rodgers said. "It was always going to be tough away at this level and home games were going to be important for us.
"So it wasn't to be but we will play the remaining games now, obviously the next game will be against Monchengladbach.
"We expect it will be tough again and we will have to do the very best that we can."
Information from the Press Association was used in this report.