Toyota Gazoo Racing team principal Jari-Matti Latvala believes Elfyn Evans suffered an uncommon issue with his GR Yaris at Rally Finland.
Evans is third in the standings with five rounds to go in the WRC schedule, behind rivals Ott Tanak and Thierry Neuville.
The Briton suffered an issue with the driveshaft during Stage 12, costing him valuable time and points in the heat of the title battle.
Evans has been performing consistently this season, finishing every rally in the top six and driving to second place four times.
Elfyn Evans suffered an ‘unusual’ driveshaft failure at Rally Finland
The driveshaft failure isn’t the first piece of bad luck to hinder Evans’ title challenge after damaging punctures in Kenya, Portugal and Sardinia.
Latvala said you always have to take a chance in motorsport despite the battle for the championship against the Hyundais of Neuville and Tanak.
He said via motorsport.com: “It’s an unusual [failure]. I don’t think we have ever had a driveshaft problem.
“But of course, there is always a little bit of risk in motorsport that some parts, when you machine them, that something has gone wrong and that is why it has failed.”
The incident is also costly for Toyota in the FIA World Rally Championship for Manufacturers, they trailed Hyundai by one point heading into Finland.
Evans added: “There’s nothing you can do. There’s no point in crying about it, you just have to get on with it.
“I was coming into a junction, I was back to the throttle, and it was clear we lost drive to one of the wheels.
“Obviously, it spun us around immediately and from there on it was a case of just nursing the car back.”
Thierry Neuville struggled with the handling of his Hyundai i20
The championship leader, Neuville, won the season opener at Monte Carlo and held a slim eight-point advantage over his nearest rival Tanak.
The Belgian has been competitive in Finland moving into third place on Friday but floundered while tackling Stage 13.
The Ouninpohja Stage returned for this year’s edition, mostly thanks to the introduction of virtual chicanes, which had been eagerly anticipated before the rally. After getting its place back on the schedule, it even gained its own merchandise range.
Neuville said after struggling on the stage: “We are going to do a few more steps this afternoon, with different springs but the performance isn’t there, and maybe the Toyota has improved a bit.
“But generally I feel like we could be faster if we had a bit more consistency in the grip changes.”