The Hoops boss confirmed that the Nigeria international missed the team bus from the hotel and had to catch up by taxi. In the event, Ambrose replaced the injured Victor Wanyama for the start of the second-half when the visitors were behind to an Allesandro Matri goal, before Fabio Quagliarella notched the second in the 65th minute.
Lennon was in no mood to expand upon the Ambrose incident, saying: "There was disciplinary action taken against him but it wouldn't have affected the team selection tonight."
Pressed on the issue, the Northern Irishman "Is this the best line of questioning we can do here? Are we not going to talk about the game, are we going to talk about things which aren't important?"
Lennon was more comfortable talking about what he saw as a difference in quality between the two sides was evident over the two legs and admitted it might be difficult keeping his better players for another tilt at the Champions League next season.
He said: "The difference is quality in the final third. We had good chance again tonight but we didn't take them. We played really good football, had good spells in either half and we missed what I think were very good chances to get back into the tie.
"The difference is quality, quality counts and that was the difference between the two teams over both games.
"It would be a travesty for these young players not to progress their careers after achieving so much and having played against some of the best players and teams in the world.
"While I hope they learn we won't know until we come back into the competition next July, but it is going to be very difficult (to keep them). Some of them want to progress their careers maybe out of Scotland and it is difficult to stop that progression.
"We are doing our job, bringing these young players in and developing them and hopefully selling them on for significantly more than we brought them in for, but we will have a look at the end of the season."
- Sports & Recreation
- Fabio Quagliarella
- Victor Wanyama