Naples - Napoli host Manchester City in Champions League Group A at the San Paolo in a clash neither side can afford to lose.
The maths is very simple for Napoli, if they lose they will be out while for City, a defeat would mean they would have to beat group leaders Bayern Munich in their final game and hope the Italians don't do likewise against already eliminated Villarreal.
A draw would leave both teams probably fighting for the second place spot as Bayern need just a point on Tuesday at home to Villarreal to progress to the Last 16.
Both have performed well in Europe this season in a group in which Bayern have thus far appeared a class apart.
But the ominous sign for Napoli is that City have clearly been improving with each match and if they can repeat their domestic form, then there is no reason not to suspect they could even rival Bayern for top spot.
Napoli earned a crucial 1-1 draw in Manchester in the opening group game but City boss Roberto Mancini believes his side have come on since then.
"The feeling is good for Napoli. The team has improved a lot in the Champions League," he said.
"But I know what we will find in Naples, they are playing very well at home.
"If we want to win there then we will have to play better than (in Saturday's 3-1 win over Newcastle)."
Mancini did at least have the luxury of resting playmaker David Silva and midfielder Gareth Barry for most of the Newcastle match.
"David for me could play in all the games, but sometimes he must rest. He (only) arrived on Thursday from Costa Rica (after international duty). Gareth, the same, he played in two (international) matches," Mancini said in explanation for resting the pair.
One in-form player he is likely to be counting on is Italian forward Mario Balotelli, a scorer against Newcastle who has in the past admitted he would be interested in a move to Napoli.
"He's a very important player for us, and he is becoming better and better," said Mancini of his errant countryman.
"I've told him not to waste his talent and that how good he becomes is up to him."
After last season's fine third place finish in the league which took them into the Champions League for the first time in 21 years, Napoli have been far more inconsistent this term.
Victories over AC Milan and Inter Milan have been the highs but too often they have dropped points, especially at home, from games they would be expected to win.
And coach Walter Mazzarri admits they have found the twin commitments in Europe and at home a challenge, although he believes they are equipping themselves well.
"The progress is being expressed through the way we're playing and I'm very happy with the progress we're making," he said.
"It's the first season that we're juggling the Champions League and league and we're doing well on both fronts.
"If we keep expressing ourselves at this level then I'm sure we'll win a lot of games.
"Now we look forward to Tuesday when we're playing a great team who had a stroll in the park in their league game.
"We know what to expect and we'll try to be at our best and to play our way."
Although Napoli failed to beat Lazio at the weekend, they were dominant and Switzerland midfielder Gokhan Inler believes they merely need to continue in their current vein and the results will follow.
"Now we have the Champions League and a great match against Manchester (City), we're going to give everything to progress in Europe," he said.
"We believe that with this rhythm everything is possible and I believe that if we continue on this path we can obtain great results."