Midfielders: Marco Verratti, Vitinha, Fabian Ruiz
Marco Verratti and Vitinha had a nice pair of games last weekend in which was definitely a return to form by the former and a bounceback-type performance by the latter. They should retain their starting roles this weekend as they are the two most capable players in the midfield area of PSG.
The remaining position is the never-ending conundrum Galtier has to face every weekend as there are no surefire options that make this a chalky and easy decision. The manager can explore multiple, different paths here, but the widely expected pick will probably be Fabian Ruiz. Although dull, Ruiz brings some stability and is good to link the building and the attacking phases of the Parisian game.
If Galtier goes a bit wilder, though, he would most probably choose Carlos Soler positioned further ahead and closer to the line of attack featuring Mbappe and Ekitike (unless Messi plays).
The two remaining options would be Renato Sanches and Warren Zaire-Emery, assuming the latter doesn't start on the defensive line as Hakimi makes his return to the squad and the starting XI.
Sanches will most probably get some minutes before the end of the season if only for PSG to know more about his physical status and for him to get some kilometers under his belt having missed more time this year than that he's spent on the pitch.