Police are unlikely to build a case against former coaches of Nihon University's football team over their alleged instructions to a player to commit a dangerous tackle, finding no evidence to support the allegations, investigative sources said Tuesday.

Former head coach Masato Uchida, 63, and former assistant coach Tsutomu Inoue, 29, have been questioned by the police on a voluntary basis over a possible case of assault during an intercollegiate game in May. The focus has been on whether their instructions carried the intent to injure the opponent as perceived by the Nihon University player.

During rare police investigations over such foul play, investigators also studied the statements of Taisuke Miyagawa, 20, who injured Kwansei Gakuin University quarterback Kosei Okuno with the violent tackle, and more than 200 players and other people involved.

They also analyzed images of the game in question and judged there is no evidence to determine that the instructions could be deemed unlawful, the sources said.

The police also decided that a remark such as "crush the quarterback," which Inoue admitted to having told Miyagawa, can be used in general to mean "tackle strongly" and does not necessarily amount to an instruction to injure an opponent.

Miyagawa is expected to be referred to prosecutors for alleged assault, but the injured Okuno, who has filed a criminal complaint against Uchida and Inoue, is seeking leniency for Miyagawa himself.

Miyagawa told a news conference on May 22 that he had followed the instructions of the coaches in tackling Okuno from behind.