Rafa Benitez ordered Jose Callejon and Valon Behrami to leave Napoli training early on Sunday, adding to uncertainty about their future.
Atletico Madrid have registered an interest in Callejon while Behrami, who departed following an argument with Benitez, is believed to be a target for Hamburg.
The incident comes after Lorenzo Insigne refused to talk to Napoli fans at the team's official presentation over the weekend.
But club president Aurelio De Laurentiis attempted to play down speculation about Callejon and Behrami's future, saying: "They are probably just tense because we're not selling them."
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Christian Maggio hopes former Real Madrid winger Callejon can put his distractions behind him, telling Gazzetta dello Sport: "He's a great player and we've got a great understanding."
The full-back stressed the importance of becoming sharper in defence if Napoli want to improve on recent near-misses in their attempts to win Serie A.
He said: "Benitez has asked for us to be a bit more careful at the back, particularly on dead-ball situations. If we want to win the league, then we've got to succeed in doing that."
Maggio also talked up the importance of Insigne to Napoli, adding: "He gives additional value to our side. He can give us that extra gear. Lorenzo's fantastic, entertaining and he's a lively Neapolitan."