Although it was a "shame" to lose a few hours of track time during Friday's Bahrain test, Jenson Button feels it could not have happened at a better time.
Button brought out the red flags on Friday morning just as he was able to start a race simulation run.
With his MP4-29 back in the garage, McLaren diagnosed a gearbox problem with the repairs taking much of the day.
Button, however, did manage to get out in the final hour to put in a few more laps and finished on 52 with a best time of 1:36.901.
"We had a problem within the gearbox - it took a while to change, as anything within the power-unit does these days - but we got back out at the end, and everything ran smoothly, which was good," the Brit revealed.
"It was a shame to lose that time - it's the first major issue we've had this winter; but it's better to suffer it here, rather than at a race weekend.
"We were still able to do a long-run on high-fuel this afternoon.
"The basic car is good, and there's a great deal of potential there, but there's still a lot of work to do. We have a good understanding of the power-unit, and we know how to race it, but, in terms of balance and grip, the car isn't quite there yet.
"But I know we've got some good improvements in the pipeline - and they should help us close the gap to the front of the grid."