Tottenham were dealt another huge injury blow as Cristian Romero was forced off in the early stages against Chelsea.
Despite racing into a two-goal lead against Enzo Maresca's side, a fairly innocuous turn from Romero appeared to have caused some discomfort. The Argentine defender looked to be holding his groin and was soon replaced by Radu Dragusin after 15 minutes played.
Romero looked to play on for a few moments but soon signalled to the bench which could be a damning blow for Spurs. The decision to start both Romero and fellow defender Micky van de Ven has been a rare occasion as of late for Spurs.
But having just returned from yet another injury problem, Postecoglou will be hoping his latest setback isn't as serious as first feared.
For the second successive season, Romero was unable to play through a home clash with Chelsea after also being substituted in last year's home clash.
Chelsea soon hit back following the former Atalanta was replaced with Jadon Sancho reducing the visitors' deficit to just one goal.
Prior to his substitution, Romero looked visibly upset as Tottenham fans appeared to throw missiles onto the pitch when Jadon Sancho attempted to take a corner.
Gesturing towards the home fans, the 27-year-old signalled for them to stop doing so before the game quickly resumed soon after.
In a back-and-forth first 45 minutes, it was Marc Cucurella who appeared to be Chelsea's achilles heel by twice falling over and allowing the hosts to race through on goal and score.
Dominic Solanke opened the scoring following his first mistake before Dejan Kulusevski finished off another sweeping move to double their advantage.