Chennai June 30: South Indian Superstar Rajinikanth has left for the US for a medical check-up, a source said."Rajini sir left to the US with his daughter Aishwarya last night (Wednesday). He has gone for a regular medical checkup. They will be back in mid-July," a source close to the actor told media.The source clarified that Rajinikanth is absolutely fine.He has completed the first schedule shooting of his upcoming Tamil film Kaala . The 67-year-old will return to the sets of Kaala , in which he plays a slum-lord-turned-gangster, in July. Kaala reunites Rajinikanth and Kabali director Pa. Ranjith.The film, which also stars Nana Patekar, Huma Qureshi, Anjali Patil, Pankaj Tripathi, Samuthirakani and Sakshi Aggarwal, is being bankrolled by actor-producer Dhanush.