Marcelo was forced off by a back spasm in the first half of Brazil's World Cup clash with Serbia, the Confederation of Brazilian Football (CBF) has confirmed.
The Real Madrid left-back grimaced as he hobbled to the sidelines in the 10th minute of the Group E encounter, Filipe Luis coming on as his replacement.
Marcelo initially headed towards his team-mates in the dugout, but was helped down the tunnel by the medical staff in Moscow.
A statement tweeted by the CBF read: "The full-back had a back spasm. He was treated and he's fine. Get well soon, ace!"
Filipe Luis only returned from six weeks out with a broken leg in May, and with Danilo struggling with a hip issue, Tite will hope his options at full-back are not further restricted if Brazil make it to the last 16.