Villa take on CSKA Moscow at Villa Park on Wednesday with a number of different factors affecting the possible outcome of the tie.
First of all, the Russian outfit have not played a competitive match since November and no one can be sure just how prepared they are for the crunch clash.
Secondly, CSKA have a new coach. In December, Brazilian legend Zico took over from the departing Valeri Gazzaev, who was the most decorated coach in the history of the club.
Zico may choose to play an open style of football, with flair players Vagner Love and Yuri Zhirkov to the fore or he could adopt a more defensive approach, again no one can really be sure.
Finally, the second leg of the tie is to be fought out on an artificial surface in the Russian capital. Villa have no real experience of playing on plastic, which adds to the unpredictability factor.
The Claret and Blue may have those issues in the back of their minds but Martin O'Neill and his men know that they are good enough to progress if they play to their best.
This may be a meeting of first and third in the group stages but the matchup is much more equal than the story that those positions tell.
Coin
Villa could and should have topped their group. They eased off too early and paid the price with a poor defeat against MSK Zilina.
CSKA on the other hand played at full throttle during the early stages of the competition and managed four wins from four in their group.
Undoubtedly, they will pose more than a few problems. But, Villa are one of the quickest teams in European football at the moment so it will be interesting to see how Zico prepares his side.
The Claret and Blue welcome back Gareth Barry in place of the suspended Steve Sidwell, who had a horror show at Everton on Sunday.
Emile Heskey is still nursing an Achilles tendon injury, meaning John Carew gets another chance to prove himself up front.
Curtis Davies and James Milner should also start after recovering from knocks picked up at Goodison.
If you fancy a bet on this game, then it may just be better to flip a coin rather than rely on your instincts. But, hopefully Villa will use their heads and come out on top.