With the FIFA Confederations Cup semifinals set, Janusz Michallik breaks down the two exciting matchups.

Just over a year ago Chile brought their Copa Centenario group phase to a close with a 4-2 win over Panama in Philadelphia, a result that showcased their attacking brio but also their defensive deficiencies.

Of all the teams to make it into the quarterfinals last summer, Chile haconceded the most goals. Ahead of them lay Mexico in Santa Clara — essentially a home game for El Tri — followed by a semifinal against the dangerous Colombians and then Argentina, Lionel Messi and all, in the final. Yet Chile ended up champions without conceding a single goal in those three knockout matches.

Now they have ended their Confederations Cup group matches with a second consecutive draw, this one an undistinguished 1-1 against Australia. Might they be capable of kicking on as they did a year ago, finding extra gears when it matters and flying home with the trophy?

It is possible, of course, but there are problems. For one thing this is 12 months later. The Chile team are ageing together and this, their fourth consecutive end-of-season tournament, could be taking a toll.

Theirs is a high energy form of play. At their best, when they make the ball fizz in possession and keep the opposition in a stranglehold if a move breaks down, they need constant movement. In both the last two matches, draws against Germany and Australia, it was notable that space began to open up towards the end of the first half. After looking to seize the initiative in the early stages, the team was heavy in the legs, no longer able to stay compact and their opponents came charging through the gates.

The other problem is the nature of Wednesday’s opposition, Portugal. A negative consequence of coming second in the group (topped by Germany) is that they have a day’s less rest before taking the field for the semifinal, where they take on the European champions.

Playing Portugal is the type of clash for which Chile came to Russia: as Copa America winners for the first time, they quite rightly want to parade themselves in front of the top European teams.

Group opponents Germany brought an experimental side, giving their usual starters some time off. Johnny Herrera, who kept goal for Chile in that game, declared that it was a “stupidity” to describe the Germans as their country’s second team. He was right: it’s more like a third XI. Portugal, though, are here with all that they have. Like the Chileans, they are thoroughly enjoying the fact that they wear the continental crown and there was never any talk of resting the likes of Cristiano Ronaldo this month.

A semifinal against Portugal, then, is the kind of challenge that the Chileans have been dreaming about but it comes with its own concerns. Chile gave so much space to Australia’s cultured attacking midfielder, James Troisi, in Moscow. What might Cristiano Ronaldo & Co. do with that amount of room on Wednesday in Kazan?

Similar doubts hung over the Chilean campaign a year ago in the United States but they rose to the challenge in magnificent fashion: indeed, the 7-0 quarterfinal win over Mexico in Santa Clara is probably an all-time high point of the Chilean national team, and came in a performance that was every bit as astoundingly good as the scoreline.

Can they hit that peak again when they take on Portugal or is time beginning to take its toll on Chile’s golden generation?

Tim Vickery covers South American football for ESPN FC. Follow him on Twitter @Tim_Vickery.