WITH Ireland on a must-win mission to Macedonia today, there are similar jobs in hand for Russia and Slovakia in Group B.
The trio are tied on 10 points with Giovanni Trapattoni's men sitting pretty on top of the table and all eyes will be on St Petersburg at 4.0 as Russia are the first to take the field, welcoming the tricky Armenians.
Any sort of slip by Dick Advocaat's men will be fuel to the respective dressing-rooms in Bratislava and Skopje.
The Armenians are just two points behind the chasing pack and will fancy their chances after holding the Russians to a draw in March.
Zenit midfielder Roman Shirokov misses out for the hosts, while Advocaat also has doubts over his clubmate Aleksandr Kerzhakov, who has knee problems.
Everton winger Diniyar Bilyaletdinov has warned the home side to be on their guard.
"Armenia are a very mobile and well-organised team, they move fast from defence to attack and their counter-attacks are always dangerous," he said.
"They're a technically-gifted team and not easy opponents. But we're playing at home, and we need three points."
Slovakia should have no problems dispatching of the group's weakest link Andorra at home, with their clash kicking off more than an hour before Ireland's.
They struggled to break the pointless Andorrans down away from home in March, but Vladimir Weiss's men will be confident of boosting their goal difference in Bratislava this evening.
They are without Slovakia Vladimir Weiss Jr and Marek Sapara through injury, while Miroslav Stoch and 'keeper Jan Mucha are suspended but they still should have enough to beat the Andorrans.
Meanwhile, Portugal defender Ricardo Carvalho has been ruled out of this evening's qualifier against Norway with a back injury, the Portuguese Football Federation (FPF) said yesterday.
The FPF said in a statement that the former Chelsea defender picked up the injury in training earlier this week.
Portugal have had a dismal start to the campaign, but can go top of Group H if they beat leaders Norway at the Luz Stadium tonight.
Coach Paulo Bento has engineered a remarkable turnaround, improving the side's morale after replacing the sacked Carlos Queiroz in September.
"It is a key opportunity to go first in the group," Bento said.
"We are under pressure, but it is a much better kind of pressure than what we had back in October."
Iceland and Denmark face off in the group's other encounter, kicking off just over an hour before the Portuguese clash.