Nightmare testing continues for Red Bull

The reigning World Champions have endured a nightmare opening test in southern Spain, with Sebastian Vettel completing just 11 laps over the first two days and Daniel Ricciardo being restricted to three on Thursday.

After a three-hour delay while the team continued to work on an energy store issue with engine partner Renault, the cause of Vettel's Wednesday troubles, Ricciardo's first run came to a smoking end in a matter of seconds.

Although it has not been confirmed what led to the Australian's stoppage, it is believed that the outfit is struggling with a separate packaging problem, with the battery and ERS elements said to be too close to heat sources.

Ricciardo headed out for another short run later in the afternoon, but after struggling to return to the pit lane under his own power, the RB10 was taken back into the garage, where it is set to remain for the rest of the day.