What happened: Russell pulled over at Turn 1 at Sepang with five laps remaining while holding third under the safety car. Mercedes linked the stoppage to a power unit failure and said a penalty will apply at Marina Bay this weekend.

Why it matters: Russell sits 84 points behind Antonelli with seven rounds left, so a back-of-grid start in Singapore tightens his margin for recovery. Verstappen won at Sepang from pole to extend the front-running order Mercedes must now chase through the field.

What to watch: Mercedes is set to fit a new power unit ahead of Marina Bay practice. Focus shifts to qualifying order and how far Russell can climb on Sunday.