It has proved to be a calamitous call, with Jullien subsequently testing positive for coronavirus and forcing 13 of his team-mates into quarantine.
Boss Neil Lennon and his assistant John Kennedy are also self-isolating after being ruled a close contact of the centre-back.
They were made to watch at home as another late defensive lapse allowed Hibernian striker Kevin Nisbet to fire a late equaliser and cancel out David Turnbull’s sublime free-kick in another devastating blow to the Hoops’ faint title hopes.
The 1-1 draw means they can now surely wave goodbye to their 10-in-a-row dreams, with runaway leaders Rangers now 21 points in front.
Furious fans have hit out at the decision to let Jullien take the 3,000-mile flight to the UAE despite being ruled out for four months with a serious knee injury.
But first-team coach Strachan – who took over Lennon’s dugout duties – insisted it was done with the best of intentions as he insisted Celtic did not regret flying to the Middle East amid the global pandemic.
“It was to maintain his treatment with the backroom staff, he went over there so we can get him back as fast as we can,” he said.
“Yeah, I can understand the frustration from everybody, because we end up playing with a weaker team tonight, but that could have happened if we were training at home as well.
“There’s a lot of teams up and down the country, and in England as well, who are suffering with this.
“There’s regret that one person has caught the virus but there’s not a regret in terms of the permission we got to go and the protocols that we followed, which we have done the whole season.
“It’s regrettable that we got one positive, which we could have got at any time.”
Captain Scott Brown led the list of notable absentees, with no sign of first-choice goalkeeper Vasilis Barkas, defenders Kristopher Ajer and Hatem Abd Elhamed, midfield men Mohamed Elyounoussi, Ryan Christie and Olivier Ntcham and strikers Odsonne Edouard, Leigh Griffiths and Albian Ajeti either.
Yet the champions were still able to field a team containing eight established first-teamers and it appeared they had got out of jail as Turnbull swept home a stunning set-piece with eight minutes left.
But Celtic’s Achillies heel was exposed yet again 60 seconds into stoppage time as they allowed Nisbet to ram home after failing to clear a Hibs free-kick.
“It’s a tough one to take,” said Strachan, who confirmed none of the 13 absentees will be back for Saturday’s clash with Livingston. “The players put a lot into the game. I thought we’d won it with a moment of magic but it’s a frustrating time to concede and the manner of the goal is a tough one to take.
“When you factor in the disruption we’ve had over the last couple of days, I thought the performance was very good.
“There was a lot of energy in it. A lot of endeavour which you would expect and there was moments of good quality.
“In any circumstances it’s a privilege leading a Celtic team and something anyone with a coaching career would be very proud of. I’m just gutted we couldn’t get the three points.
“Where does it leave the title race? It leaves it as more difficult. It does, but there’s still la lot of football to be played. We’ve just got to pick up as many points as we can and hope that other factors maybe change in our favour.”
Hibs failed with a late bid to force Celtic to retest their squad, having been warned by the SPFL they would face “severe consequences” if they did not fulfil the fixture.