Barcelona forward Ansu Fati has been ruled out of Wednesday's LaLiga clash against Rayo Vallecano with a knee injury.
The Spain international, who signed a new long-term deal at Camp Nou last week, was substituted 16 minutes from time in Barca's Clasico defeat to Real Madrid on Sunday after sustaining a knock.
Ronald Koeman revealed at his pre-match news conference ahead of the meeting with Vallecano that Fati was considered a doubt.
He was not pictured travelling to Madrid with the Barca squad on Wednesday and the LaLiga heavyweights have confirmed the youngster will play no part at Estadio de Vallecas.
A statement on Barcelona's official website read: "Ansu Fati has pain in his right knee. He is unavailable for selection and his recovery will dictate his return".
Fati only returned from a 10-month knee injury lay-off, which saw him suffer a number of setbacks along the way, in Barca's 3-0 win over Levante on September 26.
The teenage forward scored in that match and has featured a further five times in all competitions this term, with his only other goal coming against Valencia 10 days ago.
He has scored 15 goals in 49 appearances for the Catalan giants in all competitions, a tally that is bettered only by Luis Suarez (21), Antoine Griezmann (35) and Messi (69) – none of whom are still at the club – since his debut 26 months ago.
Koeman is also without fellow forwards Ousmane Dembele and Martin Braithwaite for the match with Vallecano, while Pedri, Frenkie de Jong and Ronald Araujo are also nursing injuries.
Barca enter the match ninth in LaLiga, with their return of 15 goals after their first nine games their lowest tally at this stage of the campaign since 2003-04 when scoring 11 times.