Manchester City defender Ben Thatcher will not face any charges from Greater Manchester Police for elbowing Portsmouth midfielder Pedro Mendes.
Thatcher has already been punished by Man City and the FA
Mendes' insistence the incident was dealt with by the Football Association - not the police - played a part in the local force reaching its decision.
The FA suspended Thatcher for eight games with a further 15-match suspended ban after the incident on 23 August.
City also fined the 30-year-old Wales defender six weeks' wages.
Thatcher had already been suspended for six games by his club following his challenge during a 0-0 draw at Eastlands, that left Mendes unconscious.
Greater Manchester Police (GMP) said in a statement: "Officers from GMP have spoken to the relevant parties involved in an incident during the Manchester City versus Portsmouth match on 23 August.
"In consultation with the injured player, the clubs and the Football Association, GMP has been informed the player would not like to pursue a complaint and has asked for it to be dealt with by the FA, not the police.
"In light of this GMP will not be investigating the incident further and considers the matter to be closed."
Thatcher still faces possible action from Lancashire Police over a clash with ex-Blackburn player Ralph Welch during a reserve game at Ewood Park in February.
That incident is still being investigated.