Real's European love affair is set to be tested

Arsenal
How they qualified
The Gunners drew both games with PSG despite being outplayed across the 180 minutes and topped their Champions League group for the first time since 2011.

Form since
Four Premier League defeats have seriously harmed their chances of landing the title and pressure is building on long-serving boss Arsene Wenger to step aside in the summer.

Transfer action
It's the same squad bar a couple of low-key departures.

Prospects
Arsenal have lost their last six ties at this stage and two of the last four defeats have come against this season's opponents Bayern Munich. Wenger's side have conceded ten goals in their last five league away matches and those defensive deficiencies are likely to prove their undoing in Wednesday's first leg in Munich.

Even if Arsenal upset the odds to progress somewhere along the line they will probably chuck in a stinker and lack the consistency at the highest level to land a first ever European Cup.

Barcelona
How they qualified
Lionel Messi was at his brilliant best with ten goals, ruining any possible Golden Boot wagrs as the awesome Argentinian is as short as 1-8 to finish as the top goalscorer. Nobody qualified with more than Barcelona's 15-point tally but they were fairly beaten at Manchester City.

Form since
Through to the Copa del Rey final and have not lost in La Liga since early October but draws away to Villarreal and Real Betis in January leave them trailing Real Madrid in the title race.

Transfer action
Barca have stuck with the same squad.

Prospects
Luis Enrique's side have scored in 37 of their 38 matches this season and are rated Champions League favourites which is understandable with a front three of Messi, Luis Suarez and Neymar.

However, they cannot be considered top value given PSG is no last-16 gimme and there is such depth of quality in the competition. Three of their four defeats this season have come when 32-year-old midfielder Andres Iniesta did not start.

Bayern Munich
How they qualified
Bayern had the most group-stage shots (118) but they had to settle for second spot after losing 1-0 away to Atletico Madrid and, more surprisingly, 3-2 at Rostov at odds of 1-4.

Form since
Ten wins and one draw since that Rostov reverse would suggest Bayern are in great nick but the results have masked some average performances. Seven of the successes were by just one goal but they lead the Bundesliga by seven points.

Transfer action
Holger Badstuber and Julian Green left the Allianz Arena.

Prospects
The Munich men have reached at least the semi-finals in six of the last seven years, including each of the last five so clearly Bayern deserve respect under a coach in Carlo Ancelotti who has won three European Cups as a manager.

Bayern have few weaknesses and a complete striker in Robert Lewandowski and must be on any shortlist but they also need to improve performances which have definitely dipped since Pep Guardiola exited the club.

Benfica
How they qualified
The Portuguese champions were statistically the worst side to reach the last 16, collecting the fewest points (eight) and Benfica were the only qualifiers not to obtain a positive goal difference.

Form since
Benfica's lead at the summit has been reduced to one point after drawing at home to Boavista and losing at Vitoria Setubal, while there was an unexpected League Cup exit at Moreirense.

Transfer action
Goncalo Guedes was sold to PSG for over £25m but Filipe Augusto arrived from Rio Ave. Exciting youngster Andrija Zivkovic was also added to their Champions League squad.

Prospects
Benfica lost home and away to Napoli and six of their eight points came against Dynamo Kiev so they look unlikely to beat Borussia Dortmund in the last 16 even though the Germans are inconsistent.

Jonas, Benfica's top goalscorer from last season, has returned from injury which is a bonus offset by the loss of left-back Alex Grimaldo who is sidelined long term.

Dortmund
How they qualified
Swashbuckling stuff from Dortmund who posted the most goals (21) and had the most shots on target (50). The eye-popping 8-4 triumph over Legia Warsaw was the highest-scoring match in Champions League history but more influential in sneaking top spot were the two 2-2 draws with Real Madrid.

Form since
Nowhere near good enough with only two wins in eight games and in six of those Dortmund scored just one goal. Saturday's 2-1 loss at Darmstadt was a coupon-buster with the rock-bottom hosts 8-1.

Transfer action
Reserve striker Adrian Ramos left for China.

Prospects
Results would suggest Dortmund are well behind Europe's best but a front three of Ousmane Dembele, Marco Reus and Pierre-Emerick Aubameyang means Thomas Tuchel's side are lively runners.

Dortmund don't seem to be focused for mundane matches but their two clean sheets in the last 14 outings came in 1-0 home wins over the Bundesliga's top two Bayern and Leipzig.

Napoli
How they qualified
Home and away wins over Benfica secured Napoli top spot but it was not all plain sailing as they were turned over by Besiktas at home on matchday three.

Form since
The Coppa Italia semi-finalists are unbeaten in all competitions since a 2-1 loss at Juventus in October. The recent 7-1 win at Bologna was Napoli's biggest ever Serie A away win and central to the rampant results has been the position switch to false nine Dries Mertens. The one-time winger has scored 13 goals in his last nine league games.

Transfer action
Manolo Gabbiadini was sold to Southampton and replaced by Leonardo Pavoletti.

Prospects
Napoli could be worth an interest at large odds, influenced by the difficulty of the last-16 draw against Real Madrid. Maurizio Sarri's side are playing some of the best football in Europe and nobody will fancy a trip to the San Paolo when it is packed to the rafters.

Paris St-Germain
How they qualified
PSG looked to be heading for top spot until a 2-2 home draw with Ludogorets cost them dear. Unai Emery's outfit had been 1-6 for the win on matchday six and they paid the ultimate price for finishing second by drawing Barcelona in the knockout phase. Marco Verratti made the most completed group-stage passes (502) and his fitness will be key for PSG.

Form since
PSG have won ten of their last 11 games and Edinson Cavani is Ligue 1's top scorer with an impressive 25 goals.

Transfer action
Julian Draxler was the headline arrival and Giovani Lo Celso was also signed. Guedes is cup-tied and Jese left for Las Palmas.

Prospects
The big-spending Parisians have hit the Champions League quarter-final ceiling in recent years but may not reach that stage seeing as Barca are waiting.

That said, Emery has players of the calibre of Thiago Silva, Verratti and Cavani in his ranks so it's not a foregone conclusion Barcelona will eliminate PSG for the third time since 2013. But anyone who backs PSG does so in the knowledge their fate may be known early.

Real Madrid
How they qualified
Patchy stuff from the champions, who had to settle for second behind Dortmund and failed to beat the Germans. Two last-gasp goals overturned a 1-0 deficit against Sporting on matchday one and a late Karim Benzema goal beat the Lisbon outfit in the reverse fixture. Real Madrid were also held to a 3-3 draw away to Legia Warsaw and Cristiano Ronaldo notched only twice in the group phase.

Form since
Broke numerous records en route to making it 40 matches unbeaten in all competitions. The Club World Cup champions are in control of the Spanish title race but exited the Copa del Rey to Celta Vigo.

Transfer action
Quiet at the Bernabeu.

Prospects
No team have ever retained the trophy in the Champions League era and, despite boasting world-class performers all over the pitch, Real don't scream out as a value bet to break the holders' hoodoo. Napoli will be a bigger threat than the odds suggest in the last 16.