Lionel Messi's desire to leave Barcelona showed no sign of impacting his on-pitch performance as he and Ansu Fati led the 4-0 dismantling of Villarreal on Sunday, marking a triumphant start to the Ronald Koeman era.

Barca have been engulfed by all manner of turmoil since losing 8-2 to Bayern Munich in their previous competitive match on August 14, with the unsuccessful attempt to force a transfer by club talisman Messi undoubtedly the major headline, but as they started their 2020-21 season they proved this is not a team to write off lightly.

Fati got the ball rolling with an impressive double in a five-minute period, before then winning the penalty that was scored by Messi, who subsequently saw a cross of his turned in by Villarreal defender Pau Torres.

Unai Emery's side tightened up in the second half, with Barca consequentially having a little less freedom in the final third, but Villarreal's slight improvement had no impact on what was an easy start for Koeman in LaLiga.

With Messi's future up in the air, Fati had seemingly been billed as the poster boy of this new era at Barca and fittingly he was their inspiration here, opening the scoring 15 minutes in with an emphatic first-time finish from Jordi Alba's cut-back.

The teenager was decisive again a few moments later, latching on to Philippe Coutinho's throughball and coolly slotting past the helpless Sergio Asenjo, who also had no answer to Messi's penalty, which was won by the omnipresent Fati as well.

Things got even worse for the visitors on the stroke of half-time, Torres poking Messi's cross beyond Asenjo as the unlikely spectre of Sergio Busquets lurked for a tap-in.

Perhaps unsurprisingly, Barca's intensity did drop after the interval and Villarreal became a more compact unit following a couple of half-time changes.

Koeman took the opportunity to give Fati a bit of a rest with 20 minutes to go, with another talented teenager – Pedri – given the chance to come off the bench for his LaLiga debut after joining from Las Palmas.

Miralem Pjanic and Francisco Trincao were also given their debuts as substitutes, with the young Portuguese winger almost adding a fifth goal when stinging the palms of Asenjo, but Villarreal managed to avoid any further embarrassment.

What does it mean? A smooth landing for Koeman

The first five-and-a-bit weeks of Koeman's reign had been anything but straightforward, from watching the fallout of Barca's Champions League humiliation to partaking in the unceremonious dumping of Luis Suarez that – in part – contributed to Messi's disillusionment.

Even just this week Messi vocalised his disdain for the Barca hierarchy following their treatment of Suarez, who earlier enjoyed a goalscoring debut for Atletico Madrid.

But once out on the pitch, Barca's baggage vanished. While this certainly remains a flawed squad, Messi, Coutinho and Fati provided a devastating reminder that it is also a group with immense attacking ability.

Fati sinks Yellow Submarine

While Messi certainly did well with all eyes on him, Fati was the standout, even more so given his age.

In scoring twice, Fati became the youngest player from Europe's top five leagues to net 10 times in all competitions since 2019-20 began, but he also won the penalty and provided a couple of key passes before his 70th-minute withdrawal.

The Griezmann conundrum lingers on

It will be hoped that Koeman finds the secret to getting the best out of Antoine Griezmann this term.

Leading the attack in Suarez's place might help in the long run, but he was practically anonymous here, touching the ball just 30 times (seven fewer than goalkeeper Neto), having only one shot and failing to create a single chance in his 78 minutes on the pitch.

Key Opta Facts

- Aged 17 years and 332 days, Barcelona's Ansu Fati is the youngest player from the top five European leagues to score 10+ goals in all competitions since the start of last season.
- Lionel Messi has become the fourth player in LaLiga history to score in 17 consecutive seasons, after Agustin 'Piru' Gainza (19), Carlos Alonso, 'Santillana' (17) and Sergio Ramos (17).
- Between Barcelona and Spain, Fati has scored seven goals in his past nine starts in all competitions, scoring with his nine shots on target and winning two penalties in his last two starts.
- Barca have scored four goals in a first half of a game in all competitions for the first time since December 2019 against Real Mallorca in LaLiga, under Ernesto Valverde.
- Koeman has won 4-0 in his first LaLiga game as Barcelona boss, the best debut in the competition for the club since Gerardo Martino in 2013 (7-0 vs Levante).
- Philippe Coutinho has made his first assist for Barca in all competitions since January 2019 against Eibar, ending with his worst run without an assist for the club in all comps (29 games).
- Villarreal boss Unai Emery has lost each of his 13 away games at Camp Nou in all competitions, conceding 10 goals in his last two (1-6 with Paris Saint-Germain in the second leg of the last 16 in the 2016-17 Champions League and 0-4 on Sunday).

What's next?

Barca go to Celta Vigo on Thursday, while Villarreal will hope to bounce back at home to Deportivo Alaves a day earlier.