Athletic Bilbao vs. Barcelona: Winners and Losers from La Liga

Barcelona started their Liga title defence with a hard-fought, unconvincing 1-0 victory at New San Mames over Athletic Club.

Lionel Messi missed a first-half penalty after the referee (questionably) decided to penalise Gorka Elustondo for a challenge on Luis Suarez, who later converted a slick volley in the second period to finally nudge his side ahead.

La Blaugrana held out for the victory despite some late pressure. Here, Bleacher Report picks its winners and losers from the game.

Winner: Sergi Roberto

Chris Brunskill/Getty Images

Sergi Roberto put in what was arguably a Man of the Match display, replacing the injured Dani Alves early on and dominating the entire right flank. After the game, Luis Enrique told journalists: "Roberto was subbed on very quickly but played a great game, very mature. Full-backs are important in our system."

Roberto got forward and breached the Athletic Club defence five or six times, hitting the byline, flashing real speed and providing a few good crosses. He also swept up defensively, showing positional awareness and quality when tracking.

Barcelona are light on right-backs until Aleix Vidal joins the team in January, but Roberto—both in pre-season and in the competitive opener—has shown he's more than able as a deputy. Lucho clearly feels comfortable with him, loaning Martin Montoya to Internazionale in order to clear space for him, and Roberto might just be a grace-saving depth option until the new year rolls around.

Loser: Gorka Elustondo

Alex Caparros/Getty Images

The referee's decision to award a penalty to Barcelona after Elustondo was adjudged to have hacked Luis Suarez down in the box was a poor one, but Elustondo's overall bad performance—outside the key decisions—dictates he must land in the losers column.

The No. 3, playing in central defence despite arguably showing his best football in the past in a screening role, hacked and slashed at everything in sight. He nearly gave away a second penalty, picked up a booking and generally looked a bit of a flight risk.

As freelance writer Chris Moar noted on Twitter, Ernesto Valverde would have been wiser to consider Elustondo in a holding role in midfield, perhaps bringing Carlos Gurpegi in alongside Aymeric Laporte instead.

Winner: Thomas Vermaelen

VI-Images/Getty Images

Thomas Vermaelen bounced back on Sunday, putting the four-goal horror show in the Super Cup last week behind him and putting in a firm, assured performance here.

A clean sheet is the least he deserved; alongside Javier Mascherano, he stymied Athletic Club with ease, sweeping up in the right areas, passing concisely and preventing Aritz Aduriz from dominating. The striker lacked appropriate service, but the Belgian did well to stop him from impacting.

There were plenty of concerns of Barcelona's back line in the build-up to this game, due to the sheer amount of injuries they'd suffered, but Vermaelen stepped up and strung it together. Well played.

Loser: Lionel Messi

Denis Doyle/Getty Images

Lionel Messi had a bad game. It's incredibly rare you'll ever utter that sentence, but it rings true following Barcelona's opener with Athletic Club.

The Argentinian forward saw an early penalty saved, missing the chance to put his side in the lead in the first half. He struggled to exert himself all evening, flashing just two genuine sparks of excitement and one trademark dribble.

His attacking threat was borderline non-existent, and he was foiled from the spot again. 

Winner: Gorka Iraizoz

Denis Doyle/Getty Images

Athletic Club pressed and harassed off the ball well, coping with Barcelona's incessant possession (76 percent by half-time, at times reaching 85 percent, per WhoScored.com) and limiting chances.

But when they did arise—and Luis Suarez's industriousness ensured Barca carved out a fair few by the time the final whistle sounded—Gorka Iraizoz was often there to stifle the danger. He made a number of good saves and some excellent sweeping claims and, of course, he palmed Lionel Messi's first-half penalty wide to prolong the agony for the away side.

He gave a very good overall performance.