Carlos Sainz suffers major Williams blow at US GP

Carlos Sainz was forced to end his FP1 session early at the Circuit of the Americas due to a gearbox issue.

With only nine laps on the board, they mark Sainz's only practice efforts for the weekend as sprint qualifying takes place later today.

Sainz limped back to the pit lane midway through the session and was told to bring the car in for a “potential issue with the gearbox”.

Williams has now communicated that Sainz's session has concluded early, but is confident it will not impact his appearance in sprint qualifying.

“Carlos has experienced a problem with his gearbox which we are investigating,” read a statement. 

“He will not join the remainder of FP1 but will be ready for Sprint qualifying this afternoon.”

Sainz topped FP1 in the USA last year for Ferrari.