The Spaniard was discharged two hours later, but is set for further tests on Monday to fully establish the severity of the problem.
Regardless, the injury does not appear to be linked to the heavy crash Lorenzo suffered last year in Thailand that caused him to miss four races.
Lorenzo is due to make his first public appearance as a Honda rider on Wednesday at the Repsol Honda team launch in Madrid alongside new teammate Marc Marquez.
Shortly afterwards, he will travel to Malaysia for the opening pre-season test of 2019, assuming doctors give him the all-clear on Monday.
Marquez is also in the process of recovering from his shoulder operation he underwent in early December ahead of the Sepang test.
Jorge Lorenzo, Repsol Honda Team
Photo by: Gold and Goose / LAT Images