Coach John Beilein said Horford will continue to work out and rehabilitate the stress fracture suffered in his right foot in December, but he will not play in a game again this season.
"We're working him hard in the halfcourt, thinking about the future," Beilein said. "I don't think it makes much sense (to play him). I don't think it's fair to him."
The decision to sit Horford will preserve a potential medical redshirt -- and also goes along with the Grand Ledge, Mich., native's wishes. Horford told WolverineNation in January he did not plan to play again this season unless the coaches approached him and asked him to.
He felt he had missed too much time and wanted to save his year of eligibility, and he also considered the fact that he still wasn't fully healthy.
Horford appeared in the team's first nine games this season and averaged 2.7 points and 3.6 rebounds.
Michael Rothstein covers University of Michigan sports for WolverineNation. He can be reached at firstname.lastname@example.org or on Twitter @mikerothstein.