Barcelona have the second-strongest defensive record in La Liga this season, letting in just 22 goals in their 29 games so far.

Atletico Madrid are top with just 12 flying past Jan Oblak, but after Barcelona shut out Getafe on Saturday and Sevilla put four in Villarreal's net the next day, the Catalans have risen to second place.

There are 10 players in the Barcelona squad that are categorised as defenders, not including midfielder Sergi Roberto, although he has played at both right- and left-back this season.

Javier Mascherano, although he would say "midfielder" if you asked him what his position is, has been converted into a centre-back at Barcelona and that's where he plays the vast majority of his games, so he is included.

Of the 10, one has played an extremely small role this season. A negligible role, in fact.

Douglas, whom Esther Blasco of Sport described as "the king of not being selected in the squad," gets an E grade. He has been picked in the Liga matchday squad just four times.

The right-back has only appeared in three games this season; in the Copa del Rey twice—against Villanovense and Valencia—and also in La Liga as a substitute in his side's 5-2 win over Rayo Vallecano.

A level up from Douglas are Adriano Correia and Marc Bartra. They do not appear regularly for Barcelona, although their performances are generally passable when they do.

Bartra has started three league games, appearing 17 times in all competitions, for a total of 616 minutes. Adriano, meanwhile has started four La Liga matches, with 12 appearances in total, adding up to 617 minutes.

Both players merit a C grade this season, although that could still improve considering there are crucial games ahead and, with an injury or suspension, they may end up with important roles.

Then come Aleix Vidal, Dani Alves and Thomas Vermaelen, who are all playing at a similar level this season.

Vidal, formerly of Sevilla, is on his way up, while veteran Alves heads in the other direction. The Brazilian has put in some good performances but some shocking ones too, and we are likely to see more of the younger man as the season continues—although Luis Enrique will always opt for Alves in the crucial matches.

Vermaelen has not featured a great deal, but with the exception of one performance at Malaga, he has generally been a safe pair of hands at the back for Barcelona.

He started the season in fine form—scoring a goal against the Andalusian side in the match at the Camp Nou—before returning to a lesser role when Gerard Pique returned from suspension. Vermaelen, Alves and Vidal deserve B grades for their efforts thus far.

A little ahead of them, in both the coach’s pecking order and in our ranking list, is Jeremy Mathieu. Especially in the matches he has played in 2016, the Frenchman has barely put a foot wrong. Sometimes he appears ungainly or confused, but appearances can be deceptive.

Mathieu is quick and that helps cover up any errors in judgement he makes, as well as being strong and experienced enough to be brought on in high-pressure situations—a useful reserve for Enrique.

He gets a B+ grade, with Lucho turning to Mathieu more often than not when one of the first-choice centre-backs is unavailable. He can also play at left-back if required.

Two players have A grades so far this season—Jordi Alba and Mascherano. Neither can claim not to have made errors, but the positive attributes they bring far outweigh the odd mistake.

Alba could be much better in the opposition box, often spurning chances put on a plate for him by Lionel Messi and Co., while Mascherano’s distribution is lacking.

But nobody can zip up and down the left like Alba—a brilliant counter-attacking weapon—while Mascherano brings intensity, commitment and drive to Barcelona’s back line.

The best defender, by some distance this season, has been Pique. An A+ grade is exactly what he deserves, both for his brilliant defensive work and his ability to start attacking moves by bringing the ball out of defence—while some Barcelona fans would also rate his social-media presence and ability to troll opposition fans just as highly.

But focusing only on what he offers as a Barcelona player is more than enough to go on. He even has a strong presence in the opposition box too, as seen by his assist for Arda Turan’s overhead kick on Saturday against Getafe.

If Pique can continue in this form, Barcelona are considerably more likely to retain their treble.