SAO PAULO, Brazil (AP) — Usain Bolt isn't sure whether he will try competing in the long jump because he doesn't want to risk a serious injury that could keep him from defending his sprint titles at the 2016 Rio Olympics.

The Jamaican said he is still evaluating the possibility of taking on the long jump, but is concerned that his preparation for the event could make him more susceptible to knee injuries.

"The plan is (to compete in the) long jump maybe before the Olympics, but I have talked to my coach a little bit and he's shown some concern about the fact that long jump can bring some problems to the knee," Bolt said yesterday at a news conference in Rio de Janeiro.

Bolt, who became the first man to successfully defend the 100- and 200-metre titles at the London Olympics, has been going back and forth about whether he will try competing in either the long jump or the 400 in Rio.

"We will sit down and evaluate if we want to do it," Bolt said. "Because if I do it, I may jeopardise my opportunity to come to Rio, so I may not do long jump. It concerns me. We will look over and see if it is possible."

Bolt earlier this month said his aim was to go for a three-peat of his Olympic sprint titles in Rio, but a couple of days later he said the long jump and the 400 were not out of the question.

The 26-year-old Bolt holds the world record in the 100 and 200.

He took time off from his promotional schedule in Rio yesterday to do some sightseeing around the city.

Bolt began his two-day trip by visiting the Christ the Redeemer statue, then took a helicopter tour over Copacabana Beach, Sugar Loaf mountain and Maracana Stadium, which is being renovated for next year's Confederations Cup and the 2014 World Cup.

On his Twitter account, Bolt posted a photo of the stadium and said: "Construction in full Usain Bolt speed ahead of World Cup football."

The Maracana will also be used during the 2016 Games, but the athletics competitions will take place at Joao Havelange Stadium, also known as the Engenhao.

Bolt also visited a local athletics facility and met with young Brazilian athletes. He received Rio's key of the city from Mayor Eduardo Paes.

Later he was expected to turn DJ at a party organised by one of his sponsors.