The Brazilian attacker netted his side's equaliser in their EFL Cup second-round clash with Fulham before being taken off with an ankle issue, as Spurs were dumped out on penalties at Craven Cottage.
Postecoglou only described Richarlison's problem as a "knock", but Lilywhites fans are eagerly awaiting an official update on his condition, while all of Bryan Gil (groin), Rodrigo Bentancur (knee), Ryan Sessegnon (hamstring) and Alfie Whiteman (ankle) are known absentees.
Should Richarlison not be given the green light to line up on Saturday, 19-year-old Dane Scarlett would be a like-for-like replacement, but his inexperience at the top level could instead see Son Heung-min shoehorned into a central role.
However, there is still a chance that Richarlison could shake off his concern in time for the weekend, allowing Son and Dejan Kulusevski to take up their usual positions in support of the South American.
Having all been named on the bench at Craven Cottage, Pape Sarr, Yves Bissouma and James Maddison will return to a formidable engine room, and the same can be said for Destiny Udogie and Pedro Porro in the full-back areas.
Only a couple of weeks on from an unfortunate deflection against Brentford, Micky van de Ven turned the ball into his own net in midweek, but the Dutchman will continue alongside Cristian Romero at the back, as Fraser Forster hands the gloves back over to Guglielmo Vicario.
Tottenham Hotspur possible starting lineup: Vicario; Porro, Romero, Van de Ven, Udogie; Maddison, Bissouma, Sarr; Kulusevski, Richarlison, Son