Hong Kong - World rugby chief Bernard Lapasset has ruled out the full 15-a-side game following the sevens format into the Olympics and underlined the importance of the sport's drug-free image.
Lapasset, chairperson of the International Rugby Board (IRB), said the extra time required to stage a 15-a-side tournament meant integrating the format into the summer Games would prove impractical.
"The 15s is probably the top sport at the moment in the control of the IRB but it is difficult to integrate the system into the Olympic programme because it's a short time," Lapasset said on the sidelines of the showpiece Hong Kong Sevens tournament.
"The two disciplines are with us pushing in different ways to compete for the benefit of rugby union. That is the concept -- that we have the same rules, the same core values and the same athletic guys on the field.
"It's very important for us to have the two disciplines in the same union."
The IRB is hoping the world-renowned Hong Kong Sevens, where thousands of fans cheer on 24 teams over three days of rugby, will reinforce interest in the sport ahead of its Olympic debut in Brazil in 2016.
Lapasset said he expected new nations to emerge in the sport as teams compete for a place in the Games.
He also spoke of the importance of the code's doping controls and anti-drug image.
"Clean rugby is a key message that we have around the world," he said.
Figures released by the IRB on Monday showed that it conducted 1,293 doping tests last year, about half of them on sevens players, resulting in just four failures.
Two of the violations were for cannabis, one was for "the attempted use of a prohibited substance" and one for anabolic steroids, the board said in a statement.