Reports in the Italian media claim Mihajlovic met Napoli officials and reached an agreement to move to Stadio San Paolo next term, with Rafael Benitez tipped to leave Naples amid talk of a return to the Premier League.
Benitez is reportedly in contention to replace Manchester City manager Manuel Pellegrini for a solitary season ahead of Pep Guardiola's possible arrival in 2016.
However, Sampdoria poured cold water over the ongoing speculation with the club fifth in the league standings and in the hunt for European football.
"With regards to the stories that appeared this morning about a supposed meeting last week with Napoli directors to sign a deal for the following seasons, Sinisa Mihajlovic firmly rejects this version of events and is astonished that destabilising stories on his future and that of Sampdoria players can emerge in the days before a very important game," the statement read.
"The club, the coach and the team are concentrated only and exclusively on this match and the sporting objectives to be achieved in this important final stage of the season."
Sampdoria travel to fourth-placed Napoli on Sunday.
