Samaras will undergo a scan today after limping off just before half-time with a hamstring strain with the Celtic manager already fearing the player could be out for a fortnight.
If that proves to be the case he will miss Sunday's William Hill Scottish Cup tie against Raith Rovers, the league match with Inverness Caledonian Thistle the following weekend, and then the home leg against the Italian champions.
With Samaras at risk of missing that match it now places greater pressure on Celtic to keep a hold of Gary Hooper beyond the transfer window deadline this evening. "Georgios may have a slight hamstring strain but he will be scanned [today] and we're hoping it's not too serious," said Lennon.
"Is it worrying? Yeah, well, I mean [it could] be two weeks. If it is more than a mild strain it will be a concern. At the minute it doesn't look too bad but the scan will reveal more and we'll know where we are [tonight], or Friday."
That was the only downbeat aspect of an otherwise positive night for Celtic, who stretched their lead at the top of the table following a double from Adam Matthews, and goals from Joe Ledley and Anthony Stokes. It was the reaction Lennon expected following the disappointment of the Scottish Communities League Cup semi-final defeat by St Mirren.
"In our last three home games we've scored 12 goals, and we're 15 points clear with Inverness getting beaten," he added. "So things aren't too bad. They showed a great mentality to bounce back so well. To be honest it could have been 10."
Hooper, who endured a rare fallow night in front of goal, has been the subject of interest from Norwich City this month, although last night Chris Hughton, the club's manager, was uncertain that his side would be able to convince Celtic to sell the striker before the deadline.
Lennon also suggested that Hooper would not be leaving the club. "If I was betting on it I'd say he will still be here – but I'm not a betting man. A lot of things happen on the last day, it's pretty frantic with agents and clubs ringing you."
Kilmarnock, who scored early in the second half through Cillian Sheridan to make it 1-1, were disappointed that a shot from Ross Barbour – that would have given them a first-half lead – was adjudged to have not crossed the line.
"The kid was adamant it was over the line" said Jimmy Nicholl, the Kilmarnock assistant manager.