Ange Postecoglou backed Giorgos Giakoumakis to bounce back quickly after the striker missed a stoppage-time penalty in a goalless draw with Livingston.
Giakoumakis saw his weak effort saved by Max Stryjek after Livi defender Ayo Obileye had gifted Celtic the perfect chance to go top of the cinch Premiership.
The Greek striker went on to miss another opportunity from six yards after the returning James Forrest had sliced the initial chance.
Josip Juranovic had netted from the spot in Celtic’s win over St Johnstone the previous weekend but it was always the plan for Giakoumakis to take the next penalty after he scored nine from 10 attempts in Dutch football for VVV-Venlo last season.
“It was my decision,” Postecoglou said. “He was the designated penalty-taker. The other day he wasn’t on the field when Juranovic took it.
“He will be disappointed but that’s the role of a striker. Strikers get the limelight when they score goals and if they don’t they have to dust themselves off and come back again, and I’m sure he will. I’m sure he understands that.
“I’m sure he has had this feeling before. Good strikers dust themselves off and, next chance that comes, they put it away. I’m sure that’s what he will do.”
Celtic had 85 per cent possession but their only shot on target in 90 minutes came when Anthony Ralston’s effort was cleared off the line by Jack Fitzwater.
Postecoglou said: “I know people will look at the end result and say we didn’t do enough but we’d be talking a different game if we took the chances we had.
“We had a penalty and a chance from six yards. I’m not sure what more you can do. We didn’t take them, which is part of football.”
Livingston boss David Martindale will wait until Monday before dealing with Obileye, who struck out at Kyogo Furuhashi off the ball in the box and received a red card.
“I didn’t see the incident but everybody has informed me that he has lifted his hand and it’s a sending-off,” Martindale said.
“I will see him on Monday. If we had lost that game I would probably have spoken to Ayo in the changing room. But I’m not going to turn a massively positive experience into a negative.
“Listen, he is an honest big lad. He has been brilliant for us, so if he has lifted his hands it’s a learning curve.
“Obviously I will not stand for it, Livingston will not stand for it, he could have let his team-mates down. But it’s his first year in the Premiership and he’s been brilliant for us. We will address the situation on Monday morning and it will get put to bed.
“I think it would have been a wee bit of an injustice if the remaining 10-12 players that took part in the game came away with nothing.
“I am speaking about big Max again in the positives – unbelievable, fantastic. A lot of pressure on him to pull that save off.”
Obileye had a penalty appeal himself late in the game when he got caught by Joe Hart as the Celtic goalkeeper came out to punch a ball into the box.
“I have not looked at it back,” Martindale said. “It’s one of those ones, you are shouting for it if it’s your team but you are probably moaning if it’s the opposing team.
“I spoke to Steven (McLean), the fourth official, and he says he doesn’t think it was a pen, so that’s good enough for me.”