The former Liverpool goalkeeper has been linked with a move to St. James' Park this summer as part of a reunion with Rafa Benitez.
Reina was Benitez's No.1 during his time as manager of Anfield and he now reportedly wants him at Newcastle.
Napoli have been linked with a new goalkeeper themselves and they are tracking Arsenal's Wojciech Szczesny.
However, Sarri has now revealed he wants to keep hold of Reina amid speculation linking him with a move away.
"He's a point of reference, he's a great lad," Sarri told TMW.