McLaren were forced to end the final day of pre-season testing prematurely due to a coolant leak.

Fernando Alonso had managed just three laps in Barcelona in Thursday's morning session before heading back to the garage.

McLaren's team did their best to fix the issue, but Alonso - who this week denied reports he could retire if the reliability problems that plagued their 2015 season do not improve - did not return to the track.

Despite the early finish, McLaren had completed 257 laps over the previous three days in testing, marking a massive improvement of just 79 in the opening test of 2015.

There was also a brief red flag in the morning session when Manor's Rio Haryanto when off the track at Turn Four, but he was unhurt in the incident.