Brazil team doctor Rodrigo Lasmar said Fred will be monitored, with Tite's men set to play Austria on Sunday in their final friendly before Russian Federation 2018.
It is too early to say, we have to see how he develops in the next 24 hours,"Brazil physician Rodrigo Lasmar said when asked for a full diagnosis on Thursday evening".
The midfielder was pictured receiving treatment after a challenge from Casemiro, and Lasmar has suggested that Fred and Brazil must wait before making an assessment over the knock. "Tomorrow we will know whether he will have to be further examined or not".
Manchester United made their first move to land Fred back in April, Shakhtar Donetsk's CEO has revealed, with the Red Devils eager to beat the competition to a £52.5 million (€60m/$70m) midfielder.
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More often than not, it limited players from speaking to other schools in the same conference or on future schedules. The so-called autonomy conferences will consider two different proposals to allow schools to cancel the aid.
"He has had an ankle trauma, but it is still too early for any evaluation, he has already begun the recovery work, he had that part in real pain".
Manchester United-bound Fred has been injured while training with Brazil ahead of their World Cup warm-up game against Austria on Sunday.
Brazil kick off their World Cup campaign against Switzerland on Sunday night, before facing Costa Rica and Serbia over the course of June in what is a noticeably competitive Group E.
Brazil talisman Neymar is the most probable replacement for Fred in midfield against Austria in Vienna but the South American's will be sweating on Fred's fitness as he has improved tremendously over the past few seasons.