Brazil star Marcelo was an early casualty for the Selecao as they looked to confirm their place in the World Cup last 16 on Wednesday.
The Real Madrid left-back started for his nation against Serbia in a game in which Tite's men need at least a point to guarantee their continuity in Russia.
But just 10 minutes in he showed signs of physical discomfort and was forced to leave the field.
While he first attempted to continue, his pain was evident, as it quickly became apparent he would not be able to continue in the Group E showdown.
Marcelo limped off with the aid of medical personnel, as Tite sent Filipe Luis into the action in a like-for-like substitution.
The Brazilian Football Confederation confirmed later that Marcelo had suffered a back spasm and was in recovery.
"The full-back suffered a back spasm while trying to accelerate," a statement read.
"He was treated and he is in good shape. Get well soon, crack!"
The full-back had previously started both of Brazil's outings at this World Cup, a 1-1 draw against Switzerland and 2-0 victory over Costa Rica.
And if the setback causes him to miss further action it would be a big loss for his nation, who also saw first-choice right-back Dani Alves withdraw prior to the tournament.