Napoli's players took the knee before their match on Saturday after the club criticised a decision to clear Inter Milan's Francesco Acerbi of making alleged racist comments to Juan Jesus.
A sports judge found Acerbi's comments to Napoli defender Jesus may have been offensive.
But the judge considered there was not enough evidence to deem them racist.
Jesus, 32, said he was "crestfallen"
by the finding, while Napoli said the decision was "astonishing".
The Serie A club vowed not to participate in anti-racism initiatives before their match against Atalanta on Saturday.
That led to the players removing a 'keep racism out' patch from the right sleeve of their jersey.
Supporters within the Stadio Diego Armando Maradona displayed anti-racism signs and chanted in support of Jesus.
Play was briefly stopped during the match between Napoli and Inter earlier in March, when Jesus went to speak to the referee about Acerbi's comments.
But the Italian federation (FIGC) said there was "no defamatory, denigrating or racist intent" to the comments and the case was dismissed by a Serie A sports judge on Tuesday because of a lack of evidence.
Acerbi, who pulled out of Italy's friendlies over the international break, denies the allegations.
Reigning Serie A champions Napoli lost 3-0 to Atalanta, with Francesco Calzona's side seventh in this season's table.