The duo came through unscathed in the reserves earlier in the week, Small scoring too as Jeffers played the first 45 minutes against Grimsby Town.
Jeffers started Wednesday's opening game of the season at Ipswich but was taken off injured against Wolves a week later while Small started the season on fire before going down with a knee problem.
The duo will join Etienne Esajas and Akpo Sodje who are both looking for their first starts in blue and white while Kenny Lunt and Yoann Folly are also battling for places in the middle.
Steve Watson could move to defence to accommodate Lunt or Folly with Richard Hinds being the most likely casualty as Wednesday go to Deepdale looking for their first win of the season.