"He will remain in New Jersey to make the most of the final stage of his recovery, making use of the excellent facilities at The Ridge hotel and the Columbia Park training centre," they said in a statement.
The 34-year-old was seen doing drills with the squad after warming up separately in boots and with the ball in a training session on Wednesday.
He had been limited to indoor work at the team's training centre with physiotherapists and fitness coaches, with Brazil being cautious about his return to action.
Neymar injured his right calf during Santos' 3-0 defeat by Coritiba last month, the latest in a long run of injuries and physical setbacks for the former Barcelona and Paris St Germain forward, who has not played for Brazil in almost three years.
Brazil have one point after opening their World Cup campaign with a draw against Morocco while Haiti are bottom of the group after losing to Scotland.
FIFA World Cup 2026
The 2026 World Cup will be held from June 11th to July 19th in the United States, Canada and Mexico. The tournament will feature 48 national teams and will be played in 16 modern stadiums.
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