Rickard Rydell has found the cause of the high fever that prevented him from taking part in round two of the WTCC in Marrakech, Morocco.
The Swedish driver underwent medical checks in Stockholm last week, after which he was diagnosed a thyroiditis – inflammation of the thyroid gland – and started treatment.
The healing process implies keeping physical activity to the minimum as Rydell recovers, which is why Honda Racing Team Sweden elected to sit out next week's Nordschleife test.
The team is hopeful he will be fully recovered in time for the Hungaroring, on May 1-3.
However, should the 47-year-old not be able to be fully fit for the race, the team did not rule out drafting in a temporary replacement at the wheel of the Honda Civic TC1.
Rydell currently sits 14th in the championship with three points to his name, having only raced in the season opener in Argentina.