Rosberg lost control of his vehicle shortly after exiting a tunnel on Saturday morning, crashing into the barriers before being flicked back through the chicane – narrowly missing the middle wall separating the track from the escape road. The 25-year-old emerged uninjured but his Mercedes was badly damaged in the smash, which occurred just hours before the qualifying race.
The accident happened at the exact spot where Austrian driver Karl Wendlinger crashed his car in 1994, putting him in a coma for several weeks.
“We think Nico locked the rears over the bumps coming out of the tunnel,” Rosberg's Mercedes team mate Michael Schumacher said over the radio during the session. “He had very low rear tyre pressures at the time, which probably contributed to the problem.”
The training session had to be halted for 13 minutes to allow for the debris to be cleared.
The morning's training session was marked by a second crash when Vitantonio Liuzzi hit the barriers just five minutes before the end of the session.
Ferrari's Fernando Alonso set the fastest time for the second session in a row, completing the circuit in one minute 14.433 seconds on Thursday.