AC Milan v Barcelona
Of course, this is an encounter between two of the most famous and romantic clubs in Europe, but in theory this actually won't be too much of a contest. Barcelona sit atop the Spanish league, having scored 28 and conceded just six in their nine games thus far (although they did drop their first points of the season on Saturday, a 0-0 draw with Osasuna), as well as a couple of wins in the Champions League thus far. Milan's form has been patchy this season, a full 13 points behind runaway Serie A leaders Roma, with three wins, two draws and three defeats to their name. Even though this game is in Milan, Barca will be favourites.
However, this game might still be worth tuning in for, simply because you might get to see some 'creative' refereeing. For the man in the middle will be one Felix Brych, whose last assignment was Bayer Leverkeusen's 2-1 win over Hoffenheim on Friday, during which he awarded a goal to Stefan Kiessling, a goal that you'll probably have seen already. If not, here it is - the more astute among you will note that the ball somehow crept into the back of the net via the side of it, having not passed betwixt the posts. Hoffenheim were understandably irked, and are currently trying to get the game replayed - and not without hope, for there is precedent in the Bundesliga for this sort of thing, remarkably.
"I had a slight doubt but the reaction from the players was clear: nobody was against the decision," Brych explained after the game. "I checked with Kiessling. But no-one, not even him said that it wasn't a goal. The ball was in the net and for everyone on the pitch it was a legitimate goal." So there you have it Leo and Mario - if you look the ref straight in the eye, seem honest and tell him something, you never know what you might get away with.
Arsenal v Dortmund
All is well in the land of the Gooner at present. Mesut Ozil continues to make them giggle like teenagers who've just discovered the joys of self-manipulation, Aaron Ramsey continues his remarkable run of form and they finally actually did walk it in eventually, as Mos from The IT Crowd has been saying all these years. While their start to the season has been undeniably impressive, especially when set against the bile and recrimination with which it began, they haven't actually been tested that sternly yet. They overcame Spurs and Napoli, but in both of those games their opponents were subdued (which may be churlish, because it could have been Arsenal that subdued them), so it's difficult to assess just how good they are.
Borussia Dortmund however - now, there's a proper team. A blip against Borussia Monchengladbach a few weeks back aside, Dortmund have been virtually flawless, and Marco Reus has ensured the departure of Mario Goetze can be filed (for now) under 'Actually, Not That Big A Deal As It Turns Out, We Just Wish He Hadn't Signed For Those Bastards'. Therefore, the visit of Dortmund to the Emirates will give some indication of whether the question posed in the Sunday Mailbox - Are Arsenal back? - can be answered in the affirmative.
Real Madrid v Juventus
Sure, it's obvious, but some things are obvious for a reason. A game between two giants, two behemoths - the footballing equivalent of Mega Shark vs Giant Octopus. Or something like that. It's big, anyway.
Of course, this will be a fascinating game for reasons other than the size of both clubs, not least to see how Juventus react to having their knickers pulled down and their botties spanked raw by Fiorentina at the weekend. Antonio Conte's boys were 2-0 up at half-time and cruising, but a head-spinning second half and a Giuseppe Rossi hat-trick later, and they were on the rough end of a 4-2 defeat. In addition, the midfield scrap between this pair will be quite the battle. In Andrea Pirlo, Arturo Vidal and Paul Pogba, Juve have arguably the best balance of touch, passing and power of any midfield three in Europe, leaving Real with quite a task to contain them. Plus, it'll be interesting to see who Carlo Ancelotti starts with up front. Patience with Karim Benzema seems to have worn thin (he has just two from eight starts in La Liga), and youngster Alvaro Morata started the 2-0 win against Malaga at the weekend. At home to Malaga is one thing, but at home to Juventus is quite another.
And then there's whether Real Madrid's Gareth Bale (nope, still looks weird) can start his (thus far) stuttering career with the Spanish big boys. Bale was moved to deny that he's completely broken at the weekend, and it wasn't exactly a galloping shock that a player who had spent the summer waiting by the phone, rather than training or playing games, didn't start the season like a greyhound from the traps. Of course, the people of Madrid aren't exactly known for their patience, not least the chap who signed the £86million cheque, and with the name of the injury boogeyman Jonathan Woodgate already being (prematurely) invoked, Bale will want to make an impression sooner or later.
CSKA Moscow v Manchester City
With Bayern Munich seemingly accelerating down the Autobahn at present (12 wins and two draws in their last 14 competitive fixtures), and Viktoria Plzen just looking quite, well...not good enough, the two matches between CSKA and Manchester City are going to decide who progresses to the last 16 and who becomes one of the favourites for a different trophy entirely.
That was certainly the thoughts of Manuel Pellegrini, speaking after victory over West Ham: "I think that 50 per cent of the chances to go into the second round of the Champions League will be playing next Wednesday in Russia." Quite.
The good news for City is that their opponents have taken just one point from their last five Russian Premier League matches and haven't even scored in the process, conceding nine. Goals from Hulk and Roman Shirokov for Zenit pushed the title holders down to sixth place, and there is talk of crisis at the Arena Khimki.
The good news for CSKA is that City's away form could best be described as sluggish this season, and there is no guarantee that captain Vincent Kompany will have returned to fitness in time for the game.
The good news for the rest of us is that the match is a 5pm kick-off, which means tea, digestives and some early-evening interest.
Austria Vienna v Atletico Madrid
After years of promise, almost-theres and 'glorious' failures, Atleti finally seem to have a proper team. Diego Simeone's side look very much like the real thing, and might well emerge as the primary challengers to Barcelona domestically, if those chaps in white across town can't pull themselves together.
Indeed, they seemed to announce they're the real thing in Europe too with a highly-impressive win away at Porto last time out, a win that means they will basically qualify for the knock-out stages if they beat Vienna, and Porto don't lose to Zenit St Petersburg. After selling their best player, Atletico Madrid appear to have found something more substantial.
Nick Miller - follow him on Twitter