Kansas City Chiefs star Tyreek Hill was cleared to resume playing on Friday after the NFL said it was unable to determine whether he was responsible for an alleged assault which left his infant son with a broken arm.
In a statement which followed a four-month investigation by league officials, the NFL said it could not be certain Hill had breached the league's personal conduct policy.
It followed a similar finding by prosecutors and law enforcement in Kansas City, who said they could not prosecute Hill or his partner Crystal Espinal, even though they were certain a crime had occurred.
Hill and Espinal's son, who was three when he sustained the injuries, has been removed from the couple's custody following the incident.
"In conducting our investigation, we have taken great care to ensure that we do not interfere with the county's proceedings or compromise the privacy or welfare of the child in any way," the NFL said in a statement.
"Local law enforcement authorities have publicly advised that the available evidence does not permit them to determine who caused the child's injuries.
"Similarly, based on the evidence presently available, the NFL cannot conclude that Mr. Hill violated the Personal Conduct Policy. Accordingly, he may attend Kansas City's training camp and participate in all club activities."
The league said Hill would have to undergo clinical evaluation and therapeutic intervention as a condition of his return.
It added it would review its handling of the case if "further information becomes available through law enforcement, the pending court proceeding, or other sources."
In a statement on Friday, Hill insisted the allegations against him were "false."
"I am grateful for so many things and grateful for so many people who have supported me during this challenging time," he said.
"I fully respect and accept the NFL's decision."
Hill, who in 2014 was kicked off the Oklahoma State University football team for punching and choking Espinal, had also been recorded threatening his partner.
In an audio tape which emerged in April, Espinal confronted Hill about their son's injuries, saying that their three-year-old was "terrified" of his father.
Hill replies: "You need to be to terrified of me too, bitch."
The 25-year-old had been barred from all team-related activities following the leak of the recorded conversation with his partner earlier this year.
However the Chiefs welcomed Hill back into the fold following the league ruling, saying that it was "appropriate" for him to return to the team.
"We are glad to welcome Tyreek back to the team and look forward to the start of training camp next week," the team added.
Hill is regarded as one of the best receivers in the NFL and was a key pillar of the offense that took Kansas City to the AFC Championship Game last season.