The 32-year-old winger replaced Josh Earl in the starting XI, with him expected to slot in a left wing-back.
Sinclair came off the bench in last Saturday's 1-0 win at Peterborough to take the place of Earl.
It was the only change to the side, with PNE boss Ryan Lowe sticking with Cameron Archer and Emil Riis as the partnership up front.
Among the substitutes there was a place for Bambo Diaby, the defender having had a 70-minute run out in the reserves in midweek.
Reading included former PNE loanee Brandon Barker on their bench, the winger having signed as a free agent this week having been released by Rangers.
PNE: Iversen, van den Berg, Bauer, Hughes, Potts, Whiteman, Browne, Johnson, Sinclair, Riis, Archer. Subs: Ripley, Rafferty, Diaby, Lindsay, McCann, Ledson, Evans.
Reading: Hein, Yiadom, Morrison, Holmes, Rahman, Rinomhota, Drinkwater, Ince, Hoilett, Swift, Joao. Subs: Southwood, Abrefa, McIntyre, Meite, Camara, Dele-Bashiru, Barker.
Referee: John Busby (Oxfordshire)
