Three-time Olympic gold medal-winning hockey legend Balbir Singh Sr. has been admitted to a hospital here after he complained of difficulty in breathing. Balbir Sr, 94, is currently admitted in Respiratory Intensive Care Unit (RICU) of the PGIMER, Chandigarh. A doctor attending on Balbir Sr told PTI on Thursday that an endotracheal tube has been inserted, which serves as an open passage through the upper airway. "The purpose of endotracheal intubation is to permit air to pass freely to and fro from the lungs in order to ventilate the lungs," the doctor said. His condition had shown mild improvement since Wednesday. However, the doctors were closely monitoring the condition of the triple Olympic gold medallist and will continue to remain in the hospital for the time being. Notably, in 2012 London Olympics, the iconic centre forward was honoured as the only Indian among 16 chosen Olympic legends across modern Olympic history. His world record for most goals scored by an individual in the men's hockey final of the Olympics still remains unbeaten. He had scored five goals in India's 6-1 victory over the Netherlands in the gold medal match of the 1952 Helsinki Games. He was conferred with the Padma Shri in 1957 and was also manager of India's only World Cup winning team in 1975.