"Nico is not participating in football right now," Harbaugh said. "I don't have a crystal ball as to if his mind would change on that. I know he's not currently on the team."
Collins had 78 receptions for 1,388 yards and 13 touchdowns over his three-year career and originally announced his intent to return for his senior season. He had 37 catches for 729 yards and seven scores last year but reportedly decided to opt out of this season before the Big Ten announced its plans to return.
It's a significant loss for a team that also had to replace quarterback Shea Patterson, four starting offensive linemen and wide receiver Donovan Peoples-Jones, who decided to skip his senior season and enter the NFL draft. Still, Harbaugh said his other receivers have been "really good" this offseason, specifically giving praise to Giles Jackson, A.J. Henning, Cornelius Johnson, Ronnie Bell, Roman Wilson and Mike Sainristil.
"One of the really good things about our offense's growth has been the receiving group." Harbaugh said. "Their ability to get separation, to gain separation, create separation, and to catch the contested catches."
The question is who will be throwing for No. 18 Michigan when it opens its season Saturday at No. 21 Minnesota.
While Harbaugh said Joe Milton, a redshirt sophomore, has been practicing with the first-team offense, he declined to confirm he would start, saying quarterback Cade McNamara has "closed all gaps as well."
"Naming any starter at this point, it's a daily thing, right up until the game time," Harbaugh said. "Tough for me to say that definitely anybody is going to be starting. We have to test Friday before we leave to be able to make the trip and test negative on game day to be able to play."
Harbaugh said there aren't currently any players who can't play Saturday because of COVID-19. Harbaugh, who has one year left on his contract, also said there are no updates on the status of his contract, saying only there have been "bigger fish to fry."