From its new tackling rules to its investment in CTE research, the NFL has made clear progress in addressing player safety. Now, If only the league could only explain its policy on child safety.

Adrian Peterson missed all but one game during the 2014 season while the NFL aggressively investigated child abuse allegations against the star running back. Then the league fought vigorously in court to ensure its suspension of Peterson was upheld and prevailed. Which makes the league’s handling of allegations that Buffalo Bills running back LeSean McCoy has abused his 6-year-old son and his ex-girlfriend even more curious – and concerning.

More:LeSean McCoy's ex-girlfriend speaks out about assault claims: 'Every day I live my life in fear'

More:Bills' McCoy says child abuse allegations are 'ridiculous'

This is the same league that in 2013 suspended Ray Rice indefinitely for domestic violence. The same league that in 2017 suspended Ezekiel Elliott for six games for domestic violence. And same league that has operated in a puzzling manner this week.

On Friday, McCoy’s ex-girlfriend, Delicia Cordon, held a news conference during which she reiterated allegations that McCoy abused her and his 6-year-old son. She said other women have contacted her to allege McCoy had “physically abused them, taken back other gifts he has given them, and exhibited aggressive behavior towards them and towards his child.”

The NFL’s public response? Silence.

The league did not respond earlier this week to an email from USA TODAY Sports regarding a potential NFL investigation into the allegations of child abuse and whether McCoy’s status might be in jeopardy. Cordon's attorney, Tanya Mitchell Graham, said Friday the NFL has not contacted Cordon.

McCoy called allegations that he abused his son "ridiculous" Wednesday. "These people honestly have so much to gain by doing this," McCoy told reporters. "But I'm not going to sit here and spend too much time even talking about it. It's crazy. It's ridiculous. Everything I do is for my little man, my son. And If I didn't care, I wouldn't be fighting for custody of my boy."

By coincidence, on Friday Major League Baseball placed Addison Russell of the Chicago Cubs on leave just hours after Russell’s ex-wife detailed through her Instagram account allegations of domestic abuse against Russell. MLB's action stood in disturbing contrast to the NFL’s inaction.

And there was reason for the NFL to act.

In July, a friend of Cordon’s alleged on Instagram that McCoy abused his son. And earlier this week, Stephanie Maisonet, the mother of McCoy’s son, shared details of alleged child abuse and filed an affidavit stating she has reported the abuse to Child Protective Services.

McCoy has faced no criminal charges stemming from the allegations. But Elliott was never charged and yet the NFL investigated and issued a significant penalty. So why has the league failed to act, or failed to publicly explain how they’re handling a case involving the safety of a 6-year-old boy?

Addison, the Cubs shortstop, has denied allegations of domestic abuse, too. But MLB put him on administrative leave despite no reported criminal charges against him while McCoy, the Bills’ leading rusher, is expected to play Sunday when Buffalo plays the Minnesota Vikings.

The NFL long ago overtook MLB as America’s most popular sport. But when it comes to handling matters of abuse, at least on Friday, the NFL had plenty to learn from the American pastime.