Italy boss Cesare Prandelli has surprisingly labelled Friday's game against Estonia as his toughest test since taking charge.
Although Estonia are considered as minnows of the world game, the Azzurri boss fears that his side may struggle at the end of a long season.
"This is the most difficult game of my tenure," he noted at Coverciano on Monday. "The game against Estonia will be decisive.
"I want a squad of players which will make sacrifices as this game will be fundamental. Historically speaking, Italy always suffer during matches in June and September."
Italy lead Group C by five points over Slovenia and Serbia, as well as having a game in hand over those two nations.
"We've carried out fitness tests over the last few days to get some precise statistics," the Coach added.
"Once I have the full results then I'll think about picking the team. A lot will depend on the physical condition. Seeing the importance of the tie, I want players mentally and physically fit."
Prandelli has named a 25-man squad for the Modena game, but he's lost Thiago Motta of Inter to injury and he refused to select Roma's Daniele De Rossi.
"It's sad to say it, but De Rossi was not left out for technical reasons," Prandelli added after De Rossi was handed a three-match ban for an elbow in the Week 35 win at Bari.
"If he finds that consistency and that serenity that he seems to have lost in these last few months then the doors to the national team will always be open.
"But I won't tolerate certain behaviour on the pitch and I've said this since day one."
As Italy close in on a place at Euro 2012, Prandelli did warn players with hopes of making the tournament that they had to be first team regulars next term.
"From August those individuals who don't play that often will find it tough to be selected for Italy," he added.
"Hopefully we'll be even closer to the European Championship by then and we have to be ready for it. This is just a general consideration, I'm not talking about any player in particular."
However, that statement did sound like a warning to Antonio Cassano who faces some stiff competition for a place at Milan next term.
"Cassano may have to start using his elbows to find his space in the team. In general, players lose their self belief when they don't play that often."
The tactician was also asked for reasons as to why Milan's Christian Abbiati and right-back Ignazio Abate have been ignored.
"I haven't thought about Abbiati because I have Gigi Buffon. Behind him I want to use the youngsters.
"Abate had a good second half of the season, but using new players at this time of the campaign is a bit risky."