Race organisers have made changes to the Sochi circuit in the wake of Carlos Sainz's huge crash a year ago.
Recalling his 2015 practice crash in which the Spaniard's Toro Rosso was buried deep beneath Tec-Pro barriers before he was airlifted to hospital, the 21-year-old said this week: "I'd say [it was] the biggest crash of my career so far."
Formula 1's governing FIA has confirmed that, ahead of the 2016 Russian Grand Prix, the run-off just ahead of the Tec-Pro barriers at turn 13 "have been laid with asphalt".
The FIA also said that the "guardrail straight on at T13 has been replaced by wall blocks".
