Celtic manager Ronny Deila accepted responsibility for Celtic's Scottish Cup semi-final defeat to Old Firm rivals Rangers after his side lost 5-4 on penalties following a 2-2 draw at Hampden Park on Sunday.
Former Hoops striker Kenny Miller gave Rangers - who will return to the Scottish Premiership next season - an early lead, but Erik Sviatchenko's header levelled the scores.
A stunning Barrie McKay strike put Rangers back in the lead in extra time, only for Tom Rogic to score Celtic's second equaliser to force a penalty shootout in which the Australian blazed his spot-kick over the crossbar as Rangers progressed to meet fellow second-tier side Hibernian in the final.
"Overall it is my responsibility. If that is not good enough, then it is not good enough," Deila told BBC Scotland.
"I'm very disappointed of course. It was draining. You want to win football games and in the end it was not good enough.
"It was a very hard game, but we now have to fight for the league. We have a very good chance but there are still five games left, so we look at it after that. In football, you never know."
Rangers manager Mark Warburton was "delighted" with his players and said he hopes they continue to develop and learn from the experience.
"We're delighted," he told Sky Sports. "The fans were magnificent, the players were outstanding and I thought we deserved it. Credit to both teams, but I thought we deserved it over the course of the game.
"They missed a couple [of penalties] but we spoke about experience and that's the experience, they'll be better for that. That's the character they showed, they'll be a better team for that now. Enjoy this, enjoy this but we're moving forward."