The 33-year-old returned to the starting line-up for struggling Santos as they as they travelled to title contenders Flamengo on Sunday (November 9).
Neymar had been out for the previous two months due to fitness issues but offered little as his side lost 3-2.
Spanish outlet AS said after the game: "Upon his return to the starting lineup, the Brazilian appeared slow and lacking rhythm, even hindering the plays of some teammates.
“He even protested against being substituted. If he doesn't regain his form soon, it will be difficult for him to wear the Brazilian national team jersey again in the next World Cup."
They didn’t let up there, adding: "The former PSG player was sidelined for almost two months with Santos due to a muscle injury that kept him out of seven matches.
“He briefly returned in the draw against Fortaleza before missing another game. This long absence was reflected in his performance against Flamengo.
“Even so, he showed glimpses of his quality with a dangerous free-kick and a header that almost resulted in the equalizing goal."
Neymar’s contract with Santos is likely to expire at the end of the year with links regarding a reunion with Lionel Messi at Inter Miami ongoing.