Pieters is a summer target for Toon boss Alan Pardew.
And he made clear his allegiances when roaring on Toon in victory over Liverpool.
He tweeted on Sunday: "Now checking the match #newliv Go Magpies and @TimKrul #getthose3points / Already 1-0 Papiss Cisse #keepitgoing
"Go Magpies #newliv / 2nd Goal of Pepiss Cisse 25min left..!! #keepitgoing"