French cyclist Nacer Bouhanni was badly concussed in a crash on the final stage of the Tour de Yorkshire.
The 26-year-old was knocked unconscious in a heavy fall just 25km from the finish in Sheffield on Sunday.
In a statement on Monday, the Cofidis team said Bouhanni was "still stunned" and had headaches and "vision problems", but no broken bones.
Bouhanni, who won Saturday's second stage, will have a further examination later this week.
Belgian Serge Pauwels won Sunday's final stage to secure the first race victory of his career.