Neymar is expected to be sidelined for at least a month with a muscular injury.
Santos confirmed the Brazil forward suffered a moderate (grade 2B) right hamstring problem in last week's goalless draw against Palmeiras.
Neymar, 34, will sit out several games for Santos, including their upcoming Copa Sudamericana quarterfinal tie against Atlético Mineiro.
Sources told ESPN Brasil that Santos will not take any chances with Neymar and will only allow the veteran to return to practise once he is 100%, which could be after the FIFA international break.
Santos, who also lost winger Álvaro Barreal and defender Lucas Veríssimo to injuries against Palmeiras, strengthened their squad last week with the arrivals of right-back Rodinei and midfielders Arthur Melo and Lima.
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"I can't deny that I'm very happy with the new arrivals," Santos head coach Cuca said on Sunday. "We've lost Neymar, Barreal and Lucas Verissimo and we don't know for how long these players will be out of action for."
Without the injured trio, Santos won 3-2 at Internacional on Sunday to climb to 12th in the league standings, seven points clear to the relegation zone.
