Neymar's fitness will be under the microscope on Friday as Brazil try to kickstart their World Cup campaign, anxious to avoid the kind of pitfall that has left Argentina and Lionel Messi facing an early exit.

The World’s most expensive player was subjected to rough treatment in a 1-1 draw against Switzerland, his first competitive appearance in almost four months, before hobbling out of the Rostov Arena.

Neymar limped out of training session two days later with a sore right ankle, but Brazil coach Tite has confirmed he will start against Costa Rica in Saint Petersburg.

While Neymar sporadically showed flashes of his genius against Switzerland, he appeared to slow Brazil down at other times rather than keep the ball moving.

But Tite quashed rumours he has told the 26-year-old to play more in the team's best interests.

The fate of Argentina and Messi is a timely cautionary tale for Brazil.

Argentina crashed to a 3-0 loss against Croatia on Thursday that leaves the two-time champions facing an uphill battle to qualify for the knockout phase.

Brazil's opponents on Friday, surprise 2014 quarter-finalists Costa Rica, were beaten 1-0 by Serbia in their first game in Group E, and another defeat would mean elimination.