A near-capacity crowd was expected for Saturday night's clash, which marks Smith and Warner's second BBL meeting as rivals and first since December 2013.
Sixers spinner Nathan Lyon will not join his Test teammates in suiting up, though, again missing through knee soreness.
Showers fell on the SCG early in the evening, pushing the first ball back to 7.20pm (AEDT) and condensing the game to 19 overs apiece.
With a win, the fourth-placed Thunder will snap a three-match losing streak against their traditional rivals and all but confirm their spot in the BBL finals.
The Sixers have already qualified but a victory on Saturday will boost their chances of finishing in top spot and earning hosting rights in the first weekend of the finals.
Brendan Doggett and Nathan McAndrew are rested for the Thunder, clearing the way for Gurinder Sandhu to return from injury and youngster Joel Davies to earn another chance.
The Sixers named an unnamed line-up to the side that defeated the Adelaide Strikers earlier this week.
Sydney Sixers: Josh Philippe, Steve Smith, Kurtis Patterson, Moises Henriques (capt), Jordan Silk, Hayden Kerr, Dan Christian, Ben Dwarshuis, Sean Abbott, Todd Murphy, Steve O'Keefe.
Sydney Thunder: David Warner, Matthew Gilkes, Blake Nikitaras, Ollie Davies, Alex Ross, Daniel Sams, Ben Cutting, Joel Davies, Chris Green (capt), Gurinder Sandhu, Usman Qadir.
25°C