Manager Rafael Benitez makes three changes to the side that defeated Aston Villa on Monday as the Magpies look to extend their lead at the top of the table to four points.
The Spaniard switches to a 4-2-3-1 formation to cope with Gayle's absence, with Mitrovic operating up front and Mohamed Diame dropping down to the bench.
Vurnon Anita is named among the substitutes, having returned to training this week following a layoff with an ankle injury.
As for the visitors, manager Lee Johnson makes six changes to the XI that were defeated by Fulham on Wednesday.
Aaron Wilbraham comes into the side and is expected to play at the front of a 4-1-4-1 formation, with Milan Djuric out with a stomach muscle injury and Matty Taylor relegated to the bench.
Gary O'Neil comes into a defensive midfield role, while it is all change in the middle of the park as Bobby Reid, Korey Smith and Callum O'Dowda join David Cotterill, while Jens Hegeler and Josh Brownhill miss out.
Newcastle United: Darlow; Yedlin, Lascelles, Clark, Dummett; Shelvey, Colback; Ritchie, Perez, Atsu; Mitrovic
Subs: Elliot, Gamez, Hanley, Anita, Gouffran, Diame, Murphy
Bristol City: Giefer; Vyner, Flint, Wright, Bryan; O'Neil; Cotterill, Reid, K.Smith, O'Dowda; Wilbraham
Subs: Fielding, Magnusson, Hegeler, Pack, Paterson, Tomlin, Taylor