Both players were ruled out of Scotland's international triple-header after being identified as close contacts of Stuart Armstrong, who tested positive for coronavirus.
Christie and Tierney were both advised to self-isolate for 14 days and Lennon has branded the situation “confusing” regarding the Hoops midfielder’s availability after it emerged the Gunners were pushing for Tierney to be released in order to face Manchester City.
Former Parkhead defender Tierney was reportedly diagnosed with Covid-19 back in August while Christie has not returned any positive tests for the virus.
Arsenal’s team doctor Gary O’Driscoll is understood to have held talks with the Lothian Health Protection Team, Scottish Government, and Scottish FA about the defender’s situation with Tierney said to have returned negative tests before and since the incident.
Arsenal chiefs believe he would not pose a danger if permitted to return, especially with the English Premier League’s regular and rigorous testing process.
Speaking ahead of Saturday’s Old Firm clash, Lennon said: “We are of the understanding from stories in the media and phone calls that have been made that Kieran Tierney is eligible to play for Arsenal.
"If that is the case we have been pushing hard to get Ryan involved as well."
The Celtic manager revealed the 25-year-old had been tested twice by the Scottish champions, returning negative tests both times.
Lennon continued: “He is in the same situation as Ryan was. He has had two tests with us, both negative.
"From our point of view he is good to go and we would be very confused and want answers, that Kieran Tierney is allowed to play and Ryan has been refused to play.
"It would be very confusing and I think our supporters would want to know the answers to that as well. At the minute it is very much in the air."
Lennon is already without Israeli duo Nir Bitton and Hatem Elhamed who tested positive for Covid-19 while on international duty. Striker Odsonne Edouard also returned a positive test while with France Under-21s but has completed a period of self-isolation and may be available for selection.