The left-back lasted just 10 minutes of Brazil's 2-0 Group E win over Serbia on Thursday (AEST), when he was forced off with back spasms and replaced by Filipe Luis.
Team doctor Rodrigo Lasmar suggested a hotel mattress may have been the cause of the issue, but remained optimistic that Marcelo would recover in time to face Group F runner-up Mexico in the last 16 on Tuesday.
And those positive predictions were borne out as Marcelo joined the rest of his team-mates in practice on the pitch at Samara Arena.
Brazil only arrived in the city in the early hours of Sunday morning, when it was met by a throng of reporters and a large crowd of vociferous supporters at its hotel.
The five-time champion is aiming to reach the FIFA World Cup quarter-finals for the seventh time in a row, while its opponent is looking to rid itself of "the curse of the fifth game", after falling at the second-round stage in each of the past six tournaments.