Russia coach Fabio Capello has warned his side not to take their match against Group F strugglers 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 tomorrow and Capello's side can leapfrog Portugal at the summit with a 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.
"It is very important for us to play in a compact way with good movement of the ball. It is necessary to play fast and that is what we work on at training sessions," Capello added. "I am satisfied with the current players' state and commitment, their attitude to work and the atmosphere inside the team. We are moving in the right direction."
They may not have the individual players Portugal have but they are stronger as a team and it will be massive for us to take three points.
Capello has continued to ignore the claims of experienced pair Andrey Arshavin and Roman Pavlyuchenko for the match and is also without Alexander Kokorin, Alexei Berezutsky and Yury Zhirkov.
O'Neill on the hunt for first win
Northern Ireland have problems of their own, with first-choice striker Kyle Lafferty out due to an Achilles problem and key midfielder Chris Brunt suspended. Coach Michael O'Neill has gone nine matches without a win since taking the job but is looking forward to pitting his wits against a coach of Capello's standing.
O'Neill said: "I think that you learn a lot from other managers in the group and how they prepare and you look at how Capello has done in the game.
"The strength of the team is still important but the fact that the side is predominantly picked from two clubs, Zenit St Petersburg and CSKA Moscow shows he hasn't come in and tried to be particularly clever in what he's done.
"I have a chance to come in and manage alongside a manager with the experience which he has is something I relish to be honest. It would be great for us to take three points off Russia but I think Russia is the strongest team in the group. They may not have the individual players Portugal have but they are stronger as a team and it will be massive for us to take three points."