Jari-Matti Latvala will miss Rally Argentina after breaking his left collarbone in a skiing accident.
The Finn was cross-country skiing in Lapland as part of his training programme on Wednesday when he suffered a fall.
Latvala has since undergone surgery, and will not be fit for the next round of the World Rally Championship in a fortnight's time.
Ford hopes he will be able to return to the series in time for round six in Greece at the end of May.
The team has yet to nominate a replacement for Latvala in its Argentina line-up. Petter Solberg drives its second works car, while the satellite and independent Ford team driver squads include Portugal winner Mads Ostberg, long-term Ford protege Ott Tanak, and Portugal podium finisher Evgeny Novikov.
The injury is the latest in a string of blows to Latvala's 2012 WRC title bid.
After Mikko Hirvonen left for Citroen, Latvala was promoted to number one status and expected to lead Ford's pursuit of Sebastien Loeb in the championship. But although he won Rally Sweden, crashes in Monte Carlo, Mexico and Portugal have left him back in sixth in the standings, 38 points behind Loeb, even before the injury blow.