This season's "group of death" in the Champions League has thrown up some interesting challenges for all the teams in the group.
Barcelona and Inter Milan could be considered teams in transition, although the pressure on the Spanish giants to perform is palpable. Every year Lionel Messi declares to the Barca faithful that this team will compete on all fronts and try to bring the Champions League "home". It's a promise he takes seriously, but the glory has eluded him since 2015.
Now faced with a tough group, Barca's Champions League credentials will perhaps be tested earlier than they would have expected. Borussia Dortmund seem very much like a contender to upset the gears at Barcelona.
Dortmund had a good league campaign last season and have since added to the squad and plugged gaps that may have otherwise widened into chasms. Lucien Favre's side will be full of confidence when they take on Barcelona in the opening fixture, and for good reason.
Inter Milan have been perfect in the league so far, and will need to be as close to perfect as possible to make it out of this group. They're a little short on firepower at the moment, but Antonio Conte is known to work wonders with the resources he's given (at least in the short term).
Both Barcelona and Dortmund will be wary of Inter, who will once again be hungry for success in European football.
We should mention Slavia Praha too, right? Even the most hard-headed optimists will agree that their chances are slim, if any. Still, they'll be hoping to give a good account of themselves when they face what will surely feel like six finals.
Team profiles
Barcelona: Five-time European Cup Winners (1992, 2006, 2009, 2011, 2015)
The new signings apart, the likes of Carles Perez and Ansu Fati are playing a role for Barcelona in the early part of this season. They've been fairly decent so far and their form largely seems to be on the uptick.
However, a host of new names on the pitch for Barcelona means that this team will take some time to settle. They have some good news though: their talisman Lionel Messi is set to return in time for the opening fixture of the Champions League campaign.
Player to Watch: Lionel Messi
Borussia Dortmund: European Cup winners in 1997
Under Lucien Favre, this Dortmund team has turned into a cohesive unit capable of taking on big teams. Dortmund always seemed to be prepared for big teams though; it was against some of the smaller sides that they struggled.
Although they seem to have incorporated some tactical changes to ensure they have the firepower to break down the low block, they are still prone to the odd slip-up.
Player to Watch: Marco Reus
Inter Milan: Three-time European Cup winners (1964, 1965, 2010)
There's renewed hope at Inter under the stewardship of Antonio Conte. The Italian tactician has already stamped his mark on the club and has taken them to the top of the league in these early days.
There will be questions posed of him in Europe though, given his poor record with both Juventus and Chelsea.
Player to Watch: Stefano Sensi
Slavia Praha: previously made the group stage in 2007/8
Winners of the Czech League last season, the officials from the club became popular on social media for their reaction to being drawn in the same group as Borussia Dortmund, Barcelona and Inter Milan. They will be realistic about their chances, but we may see this side be more troublesome than everyone expects.
Group analysis
One of these clubs is about to become a top contender in the Europa League by the end of this year. While optimism is surely a trait worth applauding, Slavia Praha, having only qualified for the Champions League group stages for the second time in their history, seem destined for the bottom of this group.
Based on their initial outlook, despite their engaging story, they are unlikely to shock many over the course of six games.
Barcelona will be favourites to top this group, partly for the history and caliber they've had in the competition, but mostly because they have Messi. That statement may not have been true in the past, but the team in its current state needs help.
They've begun the season without the Argentine and it is evident that their Plan B is far from the finished article, which is Plan M. Given that they will play three games at Camp Nou, and that they can be backed to get the better of either Dortmund or Inter if not both away from home, they should be the top pick to finish in the first position.
The intriguing clash is between master tacticians Lucien Favre and Antonio Conte. It's easy to get caught in the hype of Inter suddenly becoming world-beaters under Conte, but Favre has honed this Dortmund team well over the last year. That's time that the Italian has not had to build the team in his own image.
However, the situation is complicated by the very fact that it's Conte on the other end, a man renowned for building teams with his trademark style quicker than most others.
Prediction
Barcelona are likely to finish in top spot, but only just. Both Dortmund and Inter have the capability to challenge them, so the road will not be easy.
The Catalan side fill face defensively solid teams determined to break them on the counter. It's a question of which Barca turns up - the one that has for years now dismantled teams in their way to move up, or the one that capitulates under pressure.
Top spot: Barcelona
Second place: Borussia Dortmund
Europa League place: Inter Milan