Fernando Alonso says he retired from the European Grand Prix as a precaution, due to a worsening gearbox problem with his McLaren-Honda MP4-31.
Alonso was battling with Jenson Button on the fringes of the top 10 when he slowed, pulling into the garage with nine laps remaining at the Baku City Circuit.
"This was always going to be a difficult race for us – and that’s made even more difficult when you don’t see the chequered flag," he said.
"We had a developing issue on the gearbox which was getting worse and worse, so we decided to retire the car in order to prevent damage to the power unit or anything else.
"It’s a shame, but we were running outside the points, so this retirement feels a little less painful.
"The most important thing now is for the team to find a little more pace – for both qualifying and the race."
Button made progress from 19th on the grid but narrowly missed out on a point as he placed 11th.
"In terms of outright performance, we’re not quite quick enough, so to come from 19th to 11th wasn’t too bad, particularly with the straight-line speed we had here," he said.
"It was a fun race and I enjoyed it, but there are some improvements needed to raise our level of performance. I persevered as I always do when times are tough, and we’ll hopefully come out the other side."