Oyeleke, a 20-year-old who is comfortable playing anywhere across the midfield or at full-back, joined the Cobblers on Monday on a one-month loan deal from Brentford and he is expected to make his debut for Aidy Boothroyd's side at Priestfield.
Leading scorer Adebayo Akinfenwa will hope to be recalled against his former club after the 15-goal striker had to settle for a place on the bench at Aldershot six days ago.
David Artell was also among the substitutes in Hampshire after over three months out with an Achilles injury but the experienced centre-half is still not quite match fit.
Full-back John Johnson, who has spent several weeks on the sidelines due to a knee injury, is set to resume training and is close to a return to action.
Northampton, third in the table, would reduce the gap to second-placed Gillingham down to four points with a win over Martin Allen's team.
Northampton last week