Ousmane Dembele's struggles at Barcelona continued on Monday (12 February) with the France starlet missing the training session due to an upset stomach.

The 20-year-old winger joined Ernesto Valverde's side in a deal worth €105m (£93m, $129m) plus add-ons during the summer transfer window but he has since spent more time in the Catalan's treatment room than on the pitch.

The Frenchman spent more than three months on the sidelines earlier in the season after suffering a serious thigh injury which required surgery during a clash with Getafe on 16 September.

He returned to action during Barcelona's 1-1 draw with Celta Vigo in La Liga on 4 January but was forced to return to the treatment room days later after suffering another hamstring blow in victory over Real Sociedad.

Dembele made his latest comeback comeback during the goalless draw with Getafe on Sunday (11 February), with the Barcelona summer signing failing to make an impact after coming off the bench to replace Paco Alcacer in the 63rd minute.

"He (Dembele) came on at a time when I thought he could help because he is a player that can make a difference in one-on-one situations. But perhaps his lack of playing time cost him as he wasn't able to go on as often as he would have liked. But it was his first step," Valverde admitted in his press conference following the frustrating draw with the Madrid-based side.

"He didn't have much luck with that but it's better that he tried those things than to not try anything."

And Dembele's problems have continued with the club revealing that the Frenchman was unable to train with the rest of his teammates due to an stomach problem.

Meanwhile, Barcelona have not provided any update on the recovery of Thomas Vermaelen but the club confirmed that Valverde promoted six players from the second team to the training session, including two centre-backs in the form of Rodrigo Tarín and Jorge Cuenca.

"While Sunday afternoon's starters did recovery work, the remainder of the team and a handful of Barça B players — Adrián Ortolá, Rodrigo Tarín, Marc Cardona, Ballou Jean-Yves Tabla, Marcus McGuane, and Jorge Cuenca — trained as normal. Barça's French striker, Ousmane Dembélé, had an upset stomach and did not train," Barcelona informed in the club official website.

The Barcelona players will now enjoy two days off before returning to training on Thursday [18 February] to begin preparations for a crucial week in which the Catalans will visit Eibar on Saturday (17 February) before travelling to Chelsea for the first leg of the Champions League last 16 on Tuesday, 20 February.