Cueto left Wednesday's game against the Reds with lat tightness, Kerry Crowley of The San Jose Mercury News reports.
He is being examined by the medical staff and there will likely be another update on his status within the next day. Cueto was cruising along before suffering the injury after throwing his second-hardest pitch of the day. He allowed three hits, zero walks and zero runs while striking out four over 5.2 innings and was only at 68 pitches when he exited.