The Associated Press earlier reported Chauvin had been stabbed and seriously injured on Friday.
“I am sad to hear that Derek Chauvin was the target of violence,” Mr Ellison said in an emailed statement.
“He was duly convicted of his crimes and, like any incarcerated individual, he should be able to serve his sentence without fear of retaliation or violence.”
He did not give further details.
The attack happened at the Federal Correctional Institution, Tucson, a medium-security prison that has been plagued by security lapses and staffing shortages.
The person who spoke to AP was not authorised to publicly discuss details of the attack and spoke on the condition of anonymity.
The Bureau of Prisons confirmed that an incarcerated person was assaulted at FCI Tucson about 12:30pm local time on Friday.
In a statement, the agency said responding employees contained the incident and performed “life-saving measures” before the inmate, who it did not name, was taken to a hospital for further treatment and evaluation.
No employees were injured and the FBI was notified, the Bureau of Prisons said. Visiting at the facility, which has about 380 inmates, has been suspended.
Messages seeking comment were left with Chauvin’s lawyers and the FBI.
Chauvin’s stabbing is the second high-profile attack on a federal prisoner in the past five months.
In July, disgraced sports doctor Larry Nassar was stabbed by a fellow inmate at a federal penitentiary in Florida.
It is also the second major incident at the Tucson federal prison in a little over a year.
In November 2022, an inmate at the facility’s low-security prison camp pulled out a gun and attempted to shoot a visitor in the head.
The weapon, which the inmate shouldn’t have had, misfired and no-one was hurt.
Not kept in solitary
Chauvin’s lawyer, Eric Nelson, had advocated for keeping him out of the general population and away from other inmates, anticipating he would be a target.
In Minnesota, Chauvin was mainly kept in solitary confinement “largely for his own protection”, Mr Nelson wrote in court papers last year.
Last week, the US Supreme Court rejected Chauvin’s appeal of his murder conviction.
Separately, Chauvin is making a bid to overturn his federal guilty plea, claiming new evidence shows he did not cause Mr Floyd’s death.