The Swedish full-back suffered more hip discomfort towards the end of Celtic's pre-season training camp in Austria.
Lustig had only returned to action at the end of April after undergoing surgery in December to rectify serious wear and tear on both hip joints.
The 27-year-old Swede had hoped to have put the two years of discomfort he had endured behind him.
But Lustig came off after an hour of the draw with Rapid Vienna eight days ago and had to sit out the final two games of the four-match warm up series played in Austria.
They drew 0-0 with Dukla Prague on Friday night, and Adam Matthews deputised at right-back as the other contender for the position, Darnell Fisher, remained on the sidelines as he continued his rehab following knee surgery at the end of the season.
The Welshman is ready to fill the breach once again in tomorrow's second qualifying round tie against KR Reykjavik in Iceland.
Deila and his medical staff have been monitoring Lustig's condition since they returned from Austria on Friday night.
The hope is that, with a few days rest, the man who opened the scoring in the Champions League qualifier against Cliftonville this time last year will be fit and ready to go against the Icelandic champions in what will be Deila's first competitive game as manager of the Hoops.
Deila has already lost James Forrest and Scott Brown to injury, and has added Ambrose to the travelling party, despite the fact the Nigerian only resumed training with the squad at the weekend following his involvement at the World Cup Finals and visa problems which prevented him reporting to the Austrian camp.
The Hoops boss believes he has his squad as well prepared as possible, in the time-frame allowed, for their first competitive action of the season.
And he sounded bullish as he prepared to fly out today, declaring: "We will go to Iceland with a plan to win."
That plan is to take the game to KR and Deila added: "It's important we score a goal in Iceland, as many as possible."