Dummett and Fernández take over from Jamaal Lascelles and Fabian Schär at the back, with the former missing through injury and the latter suspended.
Diamé, meanwhile, replaces Ki Sung-yueng, who hasn’t travelled with the Magpies to the South Coast.
Should Dummett take up his regular position at left back rather than joining Fernández and Florian Lejeune in the centre, then Matt Ritchie will operate further forward against his former club. If not, the Scot can be expected to continue in his role at wing back.
In-form trio Miguel Almirón, Ayoze Pérez and Salomón Rondón all keep their places in Rafa Benítez’s starting line-up, with Ciaran Clark, Christian Atsu and Yoshinori Muto all returning to the bench.
There, there is also a place for Jonjo Shelvey, who will be hoping to build on his 15 minutes of playing time in last week’s thrilling win over Everton.
Newcastle United: Martin Dúbravka, DeAndre Yedlin, Federico Fernández, Florian Lejeune, Paul Dummett, Matt Ritchie, Isaac Hayden, Mohamed Diamé, Miguel Almirón, Ayoze Pérez, Salomón Rondón.
Substitutes: Karl Darlow, Javier Manquillo, Ciaran Clark, Kenedy, Jonjo Shelvey, Christian Atsu, Yoshinori Muto.