The Bahrain McLaren rider said he was out training with a friend when a car hit them from behind.
“This morning, while I was training with a friend, a car hit us from behind and took off,” Landa wrote on social media.
“The first tests confirm that everything is ok. I hope to return to training in the coming days.”
Mundo Deportivo report that the driver, who failed to stop after the incident, has been arrested.
Landa will target the yellow jersey of the Tour de France, having finished in the top 10 for the past three editions, coming closest as part of Team Sky in 2017 when he finished fourth.