Michael Cox, a 25-year-old rookie running back, is the eldest child of Michael Cox Sr., the officer who spent months recovering from serious injuries to his head and torso.

The father and son have almost never spoken publicly about what happened that night, and Michael Sr. and his wife, Kimberly, have rarely discussed it with their three children.

But Michael Jr. said the attack, which happened when he was only 6, partly shaped his life.

“Anything can happen at any time,” Michael Jr. said Monday, his first time speaking to a reporter about his father’s assault. “You have to be ready, and you have to push through things. My father went through a lot of things he shouldn’t have had to go through, but it didn’t stop him. I was taught that you decide who wins in that case.”

Michael Cox Sr., who remained with the Boston police and is now a deputy superintendent, has rarely discussed the case outside court proceedings. Since grade school, Michael Jr., sent to a Connecticut prep school and going on to play at Michigan and Massachusetts, has been toiling in anonymity, his coaches and teammates mostly unaware of his father’s past, just as his father preferred it. But Cox Sr. knew that the chance of people connecting the dots was always possible.

“I’ve spent my entire life since that night trying to make sure it didn’t have an effect on my children,” Cox said in a telephone interview from his Boston home Wednesday. “Sometimes in life, bad things happen to you. There’s no reason for that to take over the lives of your children.”