Liverpool Football Club can confirm Naby Keita was taken to hospital in Naples on Wednesday evening during the first half of the Champions League fixture with SSC Napoli.
The midfielder started the game at the Stadio San Paolo, but was substituted inside the opening 20 minutes and replaced by Jordan Henderson after alerting the team’s medical staff to back pain.
Keita was transferred to a local hospital with the club doctor, where - with the midfielder’s agreement - he underwent a number of precautionary health checks to assess his condition.
No decision has yet been taken on when the 23-year-old will be discharged.
Liverpool are scheduled to remain in Italy until Thursday morning before flying back to England.