We've looked at the first two pots that Chelsea will be getting opponents from, so we may as well look at the last. Pot four is always an interesting one, as there are usually some quality teams in here that nobody has ever really heard of. There are also usually some strong teams from bigger leagues that just haven't been in Europe for a while. We can potentially see any of the eight teams in this pot, so here's a quick look at who we may be facing this year.
Borussia Dortmund - Most of you are familiar with Borussia Dortmund even if you've never had the privilege to see them play. After surprisingly running away with the Bundesliga two seasons ago, Dortmund were a pot four danger in the Champions League last year. They'd disappoint massively, crashing out of the group stage in last place. That wouldn't stop them from winning a second consecutive Bundesliga though, and they've started the season on the right foot yet again.
Most of you will have heard of the returning stars for Dortmund already. Mario Goetze, Mats Hummels, Robert Lewandowski, Neven Subotic, and Lukasz Piszczek are just some of the most know players in the squad. Sven Bender is probably also a name many of you have heard of, and Jakub Blaszczkowski really should be a houshold name as well. Dortmund return a lot of talent, so they really should be one you watch when you have the chance.
Dortmund have had a somewhat quiet window, losing two key players while adding two to replace them. Shinji Kagawa and Lucas Barrios have left the club, while Marco Reus and Julian Schieber have joined. All told, Dortmund should be at about the same level as they were last year, and that's just a scary thought for any of Europe's top clubs.
Montpelier - Montpelier came from nowhere to win Ligue 1 last season, and because of their relative lack of European experience they are a pot four team. They've had a horrible start to this season, and after a rough summer they may struggle a bit this year. Still, they were one of the more entertaining teams in Europe to watch last year, and will likely be better than most in this pot.
Montpelier have a few names that are worth watching, as Geoffry Jourdren, Garry Bocaly, and Younes Belhanda all return to help the champs defend their title. Even if you don't know any of those names, you ought to make yourself familiar with Mapou Yanga-Mbiwa.
Unfortunately for the French club, they have lost one of the key members of their squad last season. Oliver Giroud took his talents to north London, and he'll be tasked with replacing Robin van Persie. They've attempted to replace the hulking Frenchman by adding the trio of Emanuel Herrera, Daniel Congre, and Anthony Mounier. They'll have to have some impact to replace the departed Giroud.
Malaga - Malaga looked to be taking the first steps toward becoming a powerhouse last season when they were acquired by rich ownership. They'd translate that spending onto the field as well, finishing fourth and qualifying for the Champions League. They've had a decent start to the season, but with ownership deciding not to invest in the club any more, it's hard to picture Malaga being anything more than a one time entrant into the Champions League.
Malaga return several players worth keeping an eye on. Isco is the flashy young player that will catch everyone's eye, and he'll be a fun one for the neutral to watch. Julio Baptista is a useful part, but he's injured and will be out of commission until early November. That timetable would set him up to be involved at some point though, so he's worth a mention. Jeremy Toulalan and Martin Demichelis are also Malaga players that some of you may know.
It's actually been a pretty disastrous transfer window for Malaga. They haven't added anyone of note despite a much more congested schedule for the upcoming season, but they've watched two of their best players depart the club. Santi Cazorla left for Arsenal, and Salomon Rondon has taken his considerable potential to Ruben Kazan. What makes matters worse is that neither of these brought particularly impressive fees, and it doesn't look like Malaga are planning to reinvest any of the profit anyway.
FC Nordsjaelland - The Danish outfit punched their ticket by surprisingly winning the Danish Superliga last season. They have relatively little recent history in Europe to speak of, so they will be among the bottom seeds in the tournament.
The team has lost two of their best players, but they still bring back the bulk of their squad. Jores Okore is easily the best returning player on the roster, and at 20, a good showing could see him moving to a much bigger club. Mikkel Beckmann, Morten Nordstrand, Kasper Lorentzen, and Jesper Hansen will also likely be players to watch.
As mentioned in the last paragraph, Nordsjaelland have lost two of their three best players. Andreas Bjelland has left for FC Twente, and he'll likely be a fairly solid player in the Eredivisie. Tobias Mikkelsen has also left the club to take his talents to the Bundesliga. They've added a bit of additional squad depth, but they haven't likely added anybody who will turn this club into a European power.
BATE Borisov - BATE had a long road through the qualifiers to get here, and for a second straight year the champions of Belarus have made it into the group stage. Last year BATE had the poor luck to be drawn into a group with both Barcelona and AC Milan, so they didn't have the type of results that would push them into a higher pot. They did ok for themselves though, actually managing two points including a draw with AC Milan.
BATE return their two best players from last season, as well as most of the rest of the squad that we got to see last year. Marko Simic is the club's best player in the back four, and Renan Bressen is a quality midfielder. Outside of those two, BATE don't return anyone of note.
Believe it or not, there's at least one name on this roster that most of you will immediately recognize. Alexander Hleb is still kicking around, and if you watch BATE at all you'll likely see him again. The Belarus outfit added the 33 year old in what was the only notable move for them in the transfer market this summer.
Dinamo Zagreb - Zagreb were the Croatian champions in every season since 2006, so it should come as no surprise that they were again in contention for a place in the Champions League. In all of those seasons, they only reached the group stage once, as they made an unimpressive six loss appearance last season. They'll hope to improve in their second go-around, but they'll likely be one of the biggest underdogs in the tournament. Regardless of how they fare in Europe, they're overwhelming favorites to retain their Croatian crown.
Dinamo have a pair of players who I feel are worth noting here. Sime Vrsaljko is a solid right back/midfielder and Sammir is a talented midfielder. Any success they have in this tournament will require that thos two perform fantastically, and they'll likely need quite a few others to step up as well.
Dinamo did very little in terms of reinforcing the squad this window, and I think they'd be hard pressed to recruit top players to Crotia. They did lose a key player though, as Hamburg raided the Croatian club for midfielder Mila Badelj. They'll have to hope a youngster steps up, as Badelj was probably their best player last season.
Celtic - After Rangers suffered financial meltdown, Celtic have been left as the only sort of decent club in Scotland. With Rangers at least three seasons away from a return to the top flight, Celtic shouldn't really have a domestic challenge to worry about in the near future. With that said, they'll still be highly unlikely to advance out of the group stage despite being able to make it their sole focus.
Celtic return the bulk of their title winning squad from last season. Scott Brown, Gary Hooper, Georgios Samaras, Joe Ledley, and Emelio Izaguierre will all be important parts to any success that Celtic hope to have in Europe. Victor Wanyama is probably their most interesting player though, as he's been linked to a number of top clubs throughout Europe (including Chelsea).
Celtic have probably gotten worse over the course of the summer, having only made one addition to the squad. That addition was former Newcastle keeper Fraser Forster, although he was nothing more than an afterthought for the Premier League club. They've lost two quality players though. Efrain Juarez has taken his talents to Mexico, and Sung-Yong Ki has been added to the squad at Swansea. All told, those losses hurt a lot more than the single addition.
CFR Cluj - The Romanian champions had to go the difficult route to gain entrance to the Champions League, but when the dust settled they had found themselves in the group stage. They had a fairly convincing two legged win over United-slayers Basel to seal their place in the group stage, and they have a good enough squad that the European campaign shouldn't hurt their domestic chances all that greatly.
Cluj return several key players that will be key parts in any attempt to get a result or two in the group stage. Center back Ricardo Cadu usually captains the club, and he's one of their better players as well. They also feature both Pantelis Kapetanos and Modou Sougou in attack, and those two players could be sleepers to keep an eye on.
There have really only been two major changes to the Romanian outfit over the summer window. Renan departed the club and took his skills to Sampdoria. The club brought in midfield reinforcement with the funds from the sale though, adding Ciprian Deac to the mix. Deac has picked up a knock though, and will likely miss the first two or three games of the group stage.
Steve's take on pot four - As with pot three, there's a potential nightmare in this group. Borussia Dortmund have now taken the last two Bundesliga titles. They had a rough go in the Champions League last season, but there's little reason to think that will be the case again. If Dortmund somehow get drawn with one of the bogeys from pot three, that group is instantly going to be one of the best ever assembled regardless of which clubs come out of the other two pots. Unless you want that marquee game early, Dortmund is the club to avoid.
Outside of Dortmund, there really isn't a club we shouldn't be able to handle with relative ease. Montpelier and Malaga would be on the tougher end of the pot, but I think both should be due for some regression this season and Chelsea should easily handle them. Celtic would be fun, and the travel to Scotland wouldn't be taxing at all. Any of the other four clubs would seem to provide the weakest opponents, and frankly I have no idea which one of the four would probably be the weakest. In the end, I think I'd prefer drawing Celtic and just smashing the Scottish club, all while doing as little travel as possible. The atmosphere for that away leg would just be incredible, and I really think you'd all enjoy watching Victor Wanyama play.