The victim, Indresh from Jupiter Public School in the town, was sitting with his back to the thrower at the stadium.
Javelin star likely to undergo rehabilitation process in Europe, hopeful of recovering in time for Lausanne Diamond League
Chopra had won a historic silver medal at the World Athletics Championship in Eugene on Sunday and suffered a strain in his groin during the competition.
The reigning Olympic champion admitted that his comeback from outside medal position midway into the final was 'challenging'.
The 24-year-old Chopra, who had come into the showpiece as a hot medal favourite, produced a best throw of 88.13m to finish second.
Competing in her second consecutive final in the showpiece, Rani achieved her best of the day in her second attempt but failed to cross the 60m mark in other five throws on Friday.
"Tough conditions with the weather, but happy to get my first win of the season here at Kuortane," Chopra wrote in an Instagram post.
The 23-year-old son of a farmer from Khandra village near Panipat in Haryana produced a second-round throw of 87.58m in the finals to end India's 100-year wait for a track and field medal.
Neeraj Chopra shot to fame when an 86.48M throw created history at the U-20 World Championships in Poland two years back.
The 20-year-old junior world champion had made the final after achieving the qualifying mark in his very first throw yesterday.
Neeraj Chopra re-asserted his position as the best javelin thrower in the country by setting a new meet record on his way to the gold medal.
Indian javelin thrower Neeraj Chopra suffered a groin injury while taking part in the prestigious Diamond League Meetings finals.
Javelin thrower Rohit Yadav has been provisionally suspended after he failed a dope test conducted by the NADA.