Paolo Cannavaro, brother of Italy great Fabio, and fellow Napoli defender Gianluca Grava received six-month bans while former goalkeeper Matteo Gianello was banned for three years and three months, an Italian Football Federation statement said.
Napoli, who now drop to fifth from third place in Serie A to lie 10 points behind leaders Juventus, were also fined 70,000 euros ($92,100).
The Naples club said they would appeal and criticized the soccer federation.
"Napoli do not agree with the decision of the disciplinary commission, believing that one cannot change the standings during a season. Any decision must be taken before or after a competition takes place," a statement said, adding that no offence had been committed by the club itself.
The case is the latest in a string of match-fixing and betting scandals which have tainted Italian soccer and led to a number of players arrested.
Champions Juventus, demoted in a 2006 match-fixing scandal involving referees, recently welcomed back coach Antonio Conte from a four-month ban for failing to inform authorities of match-fixing at previous club Siena.
In this case Gianello, who is no longer with Napoli, was accused of trying to fix the result of the match in order to bet on a Sampdoria victory. He was accused of trying to involve Cannavaro and Grava, both of whom refused.
The duo were accused of failing to inform authorities of the offer.
The federation prosecutor, acting on evidence gleaned from a criminal investigation in Naples, had asked for Cannavaro and Grava to receive nine-month bans and the club to be deducted one point but a disciplinary commission tweaked the sanctions.
The 1-0 win for Samp on the last day of the season in 2010 enabled them to reach the Champions League qualifying rounds.
The federation's disciplinary commission also imposed a fresh raft of points deductions, bans and fines for lower-league teams and players caught up in the widespread betting scandal.
Top-flight sides Siena, Torino, Atalanta and Sampdoria were deducted points before the season began.
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