Skipper Scott Brown dismissed fatigue as a factor in Celtic’s 69-game unbeaten domestic run coming to a remarkable end against Hearts on Sunday.
A stunning 4-0 win for the home side was the first time last season’s treble winners had lost to a Scottish team since a 2-1 defeat by St Johnstone in May 11, 2016.
It was also the first time boss Brendan Rodgers had lost a domestic game since taking over from Ronny Deila that summer and it came in the midst of a nine-game December in a season which started in July with Champions League qualifiers.
However, after officially opening Celtic’s club shop in Livingston, the 32-year-old midfielder refused to use the Parkhead club’s busy schedule as an excuse and instead claimed it had simply been a bad day at the office.
Brown said: "We have had the same season as last year, nine games in December, and we came through that and I think we went unbeaten and that was in the Champions League as well.
"It’s not about fatigue with us, it was just about one game and it is slightly disappointing.
"We have a big enough squad, we can deal with this.
"We have so many games coming up before Christmas, with the winter break coming after.
"So we need to make sure we are focused, recharged and ready to go for them."
Brown described captaining the side to their "exceptional" British record unbeaten run as "one of the proudest achievements of my career".
He stressed that confidence is not an issue and that it had only been dented by the manner of the defeat at Tynecastle, not shot.
The energetic Gorgie side took Celtic aback with a game plan which manager Craig Levein had based on Anderlecht’s 1-0 Champions League win at Parkhead earlier in the month.
Goals from 16-year-old midfielder Harry Cochrane and former Rangers striker Kyle Lafferty had Hearts 2-0 up at the break with David Milinkovic scoring twice in the second-half, one a penalty, to complete an unexpected rout.
However, with their game in hand against Partick Thistle in the Ladbrokes Premiership on Wednesday night, Celtic can go five points clear of Aberdeen at the top of the table.
The Scotland international said: "Confidence is a little bit dented with the way we lost the goals and the way we performed, but we will bounce back.
"On the day Hearts deserved their victory more than we did.
"It wasn’t like us, we couldn’t get the ball down and that was due to Hearts pressing us high up the park and putting us under pressure.
"The lucky thing about football is that we have another game just around the corner to bounce back, at Celtic Park in front of our own fans.
"Now it is all about Wednesday for us and how we can bounce back."