The striker scored for new club Palermo on Sunday but also picked up a knock and, due to the short turnaround time, has not been able to join his international team-mates in Belfast.
“It’s disappointing that Kyle isn’t in the squad but we were always going to be under pressure with players playing on the Sunday,” said O’Neill.
“He has an Achilles tendon injury which we hoped would have settled in the past 24 hours but it hasn’t and unfortunately he is unavailable, but it will provide an opportunity for someone else to come in.
“One thing I have learned over the last 18 months is there are lots of things in international football which you don’t have control over and you have to focus on those you do.”
For his part, Russia manager Fabio Capello has warned his side not to take Northern Ireland lightly.
The match, which was rearranged after heavy snow in Belfast forced it to be postponed in March, is the only competitive qualifier taking place in Europe tonight and Capello’s side can leapfrog Portugal at the summit with victory.
A repeat of the 2-0 success Russia achieved in Moscow at the start of the campaign would leave them on 15 points to Portugal’s 14, with a game in hand.
The hosts, meanwhile, are winless in 13 matches stretching over two qualifying campaigns but the Italian coach does not expect his side to go through the motions.
“The crucial moment has come. I think that everyone realises the significance of the upcoming match, its result will really have a great impact on the final group standing,” said the former England boss.
“Northern Ireland tend to play in a very compact way in defence with a great number of players. They are a physically strong, athletic team and can be very dangerous in counter attacks. That is why it is important not to lose concentration.”
Elsewhere, Italy head coach Cesare Prandelli feels he might be distracted from the football on display during tonight’s friendly meeting with Argentina — as he scans the Stadio Olimpico stands for a special guest.
The Azzurri meet the Argentinians, who will be without Lionel Messi after the Barcelona star was ruled out with a thigh strain last night, for the first time in 12 years in a special fixture organised to welcome newly-elected Pope Francis — a Buenos Aires native.
Prandelli said: “We play games every day, week in week out, but you only get to meet the Pope once in a lifetime.
“The match against Argentina has special meaning because it is our welcome for Pope Francis.
“I hope the Pope comes to watch the game. I don’t know if he’ll be able to come, but I hope he will. You don’t ask anything from the Holy Father, you just have to listen to him because he knows everything.”
Meanwhile, Steven Gerrard is sure Wayne Rooney will be able to put his troubles to the back of his mind tonight when he steps out on to the field at Wembley.
Rooney’s future has been the subject of intense speculation over the last few weeks, with the striker said to be determined to leave Manchester United for Chelsea.
Gerrard said: “Sometimes players have huge decisions to make and the spotlight is on those individuals, but I think once the game has started, you have to park whatever is going on off the pitch.”
“You have to concentrate on doing the best job you can for the country, and that does happen once the whistle goes.”