Scottish Premiership Review: Celtic booed off as Aberdeen close gap
Ronny Deila understood the Celtic fans' negative reaction to his side's 0-0 draw with Dundee as Aberdeen closed the gap at the top of the Scottish Premiership to four points.
The champions failed to break down their stubborn opponents on Wednesday, prompting the Celtic Park faithful to boo their side off at the final whistle.
"I'm angry, everyone is but we're in this together. We lose as a team. We didn't lose but we're still disappointed," Deila said.
"I understand [the booing]. The players understand that as well.
"The Celtic fans stay behind their team and they will do it now but we have to show a better side to us.
"We have to evaluate, move on and show ourselves from a different side on Sunday [in the Scottish Cup quarter-finals against Morton]."
The draw allowed second-placed Aberdeen to gain ground with a 1-0 win at Dundee United thanks to Simon Church's first-half goal.
Elsewhere, goals in the opening quarter of an hour from Callum Booth and Steven Lawless helped Partick Thistle to a 2-1 win at St Johnstone.