Celtic manager Ronny Deila has admitted that he has found the level of criticism aimed at him and his players "unbelievable".

The Scottish giants were knocked out of the Champions League in the qualifying rounds and failed to win a single game on their way to a bottom-placed finish in their Europa League group, while Saturday's home defeat to Motherwell further exacerbated the situation.

However, Celtic are still top of the Scottish Premiership and on course for the domestic treble, and Deila believes that his side will be fine if they "stay united".

"There are always ups, very high and very low, it's never something in between. But if you see the overall situation when you are leading the league, into everything, then I cannot understand everything is so unbelievably bad," he told Sky Sports News.

"It's about getting clicks on the internet and it's about selling newspapers, because it is unbelievable. There are hundreds of media and everybody needs a story and everybody gets caught into this and it affects everything. It affects the players, it affects the club and we need to stay calm inside. That is the most important thing.

"We need to be together and that's what I feel. I feel united with the players and with the staff and the people in the club. Yes we have challenges that we need to do better but when we stay united and are going forward then we can do it."

Celtic skipper Scott Brown also gave his backing to Deila, claiming that criticism of the Norwegian has been "harsh".