MatchDay Two of the Champions League continues Wednesday with Arsenal, Barcelona, AC Milan and Chelsea all in action.

Every Champions League game is brought to you live in HD this season across the FOX family of networks and DirecTV, with real-time in-game coverage on Twitter @FOXSoccerTrax and @FoxSoccerTrax2 and on-line at . Champions League continues after the international break with MatchDay Three kicking off October 18.

Because of Eastern European time zone, this week's matches have included an early kickoff time, with Wednesday's one of the more compelling games of the day: Zenit hosting Porto in St. Petersburg.

The current Russian league leaders have been on a tear, with only three domestic losses to date and a solid home record. That said, they made history of the wrong kind on MatchDay One, conceding two quick goals to APOEL, giving the Cypriots their first ever group stage win.

Led by Portuguese midfielder Danny, Zenit were expected to present a greater challenge than they have yet shown. So far, they have been marked by their timidity and lack of fluency in Europe rather than the urgency (if not flair) many think the Russians are capable of.

Zenit will have to get over their stage fright quickly as they now face a far better foe in Europa League champions, Porto. The Portuguese champs didn't lose a league game last year and are continuing that trend this season, this despite seeing their coach, Andre Villas-Boas, decamp to London. Porto have three major talents guiding them: the much-coveted striker Hulk; Uruguayan defender Jorge Fucile and midfielder Joao Moutinho. They've also never lost in Russia.

Zenit will be without defender Bruno Alves (suspended) and the injured midifelders Sergei Semak and Vladimir Bystrov. Goalkeeper Vyacheslav Malafeev is likely to play despite back spasms, while Porto are only missing the suspended Fredy Guarin.

Elsewhere there are some famous names in action but only a handful of matches that can truly be called compelling. Some of today's pairings are outright mismatches: BATE host Barcelona in a game that could see the Belarusians badly blown out, while Bayer Leverkusen can be expected to handle Belgians Genk.

But there are a couple of unexpectedly tricky tests: Arsenal play host to Olympiakos (2:30 p.m. ET, FOX Soccer Plus) in a game that cannot be considered a gimme while Chelsea travel to Valencia (2:30 p.m. ET, FOX Soccer) in a battle of somewhat diminished sides. And any other year, Marseille's home game against Borussia Dortmund might have been a nail-biter: now, both teams are off to poor domestic starts and badly need whatever they can get.

Arsenal have been battered so much of late that it feels like piling on to report the latest bits of misery: the Gunners will be without Jack Wilshere for at least five months after he underwent ankle surgery. They also got grim news on Laurent Koscielny, Gervinho and Theo Walcott: they are all out for this game, adding to an injury list that seems as long as your arm.

While Arsenal took down a last-placed Bolton side on the weekend, the team has yet to show the cohesion and flow that was the hallmark of the Gunners' recent past. In fact, Arsenal looks more like a team that has declined precipitously and, despite having some key players injured, have neither the depth to replace them nor the squad spirit to paper over the cracks. Olympiakos are hardly world-beaters, but they will present a physical challenge to a side that hasn't shown much of an ability to handle one. With Thomas Vermaelen out in the middle and the lumbering Per Mertesacker still settling in, the Greeks will look to exploit Arsenal's leakiness in the back, particularly on set pieces.

Chelsea are widely expected to be the better side in Spain, particularly after Valencia's dismal 0-0 draw to a Genk side they were miles better than a fortnight ago. Then, Ever Banega and Roberto Soldado were creative without being incisive, the latter being set up with a gift from Pablo Piatti that should have put the match to bed early, only to miss woefully.

But the Blues have their own issues, and we're not talking about the recent manufactured "controversy" surrounding Frank Lampard. Their problem is age and a lack of fluency, with brilliant moments leading to dreadful ones. This weekend, that was captured best by Fernando Torres at last looking like the striker of old when he scored a beauty against Swansea -- only to be sent off later for a ridiculous challenge. Torres at least looks like he is flickering into life; some of the other bulbs look dim if not extinguished. Lampard, who didn't get on against Swansea, is one of them; John Terry is increasingly another, a liability in the back badly hampered by his aging legs.

But Didier Drogba remains a force, and new boys Juan Mata, Raul Meireles and David Luiz have looked very good when given chances. Ramires looks like he might finally be growing into his role while Ashley Cole remains their most solid defender.

Dortmund were in such a hurry to get to their game in Marseille that their bus was ticketed for speeding. Why? Good question: They are off to an indifferent start this year, have won only once in France, and have a dismal record of scoring against Ligue 1 sides. But they rightly feel they might be turning the corner.

Dortmund are expected to field a nearly identical side to the one that got a late draw Arsenal with two weeks ago. Then, Ivan Perisic rescued the Germans late with one of the goals of the round. Last weekend, Dormund pulled out a 2-1 Bundesliga win over Mainz in similar fashion, this time behind a Lukasz Piszczek 90th minute goal. So, are the yips over and done with?

Marseille is just as shaky, with only a single domestic win in eight games. Moreover, they have a history of losing games like these at home. They will be without Andre-Pierre Gignac and Benoit Cheyrou for this one, and while they have loads of talent in the likes of Mathieu Valbuena and Loic Remy, so far Didier Deschamps has not been able to get his side to play as a unit. They will be vulnerable to Dortmund's wide attacks and have shown confusion on defense.

So, the question fans might ask is: Which side blinks first? Also on tap today are AC Milan - in a game against makeweights Plzen that they are expected to handle with ease - and Shakhtar Donetsk, against APOEL in a must-win contest for the home team. If APOEL can steal a point, we'd suddenly have to take them seriously.