After re-joining his team-mates on Wednesday, the temptation will be to put Messi straight to work.
Barca were under pressure after Atletico Madrid and second-placed Sevilla had both moved level on points with the Catalan giants.
Wins for Liverpool, Barcelona, Inter Milan, Dortmund, Galatasaray and Belgrade start off this season's UEFA Champions League group stage.
But even if the Argentine star remains as good as ever, his team will need others to step up.
Barcelona fans want Bartomeu to resign because of the club's chaotic summer precipitated by Neymar’s departure for Paris Saint-Germain
PSG stunned the football world when they prized Brazilian superstar Neymar away from Barcelona for a world record $264m
Substitute Ronaldo is shown two quickfire yellow cards after blasting Madrid into a 2-1 lead against Barcelona.
Neymar arrived back in Barcelona on Tuesday from a fleeting promotional tour to China.
At the time of the accident many passengers were standing up in the busy carriages, which increased the number of injuries.
The Brazilian superstar is at the centre of frenzied speculation linking him to PSG.
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