Langford missed the final 26 games last season after suffering a left foot injury in late December, and Izzo said that injury resurfaced recently.
When Langford originally suffered the injury last season, he was not initially ruled out for the season. He missed eight games, hoping rest and rehabilitation would be enough, but the school announced in late January that he was being shut down for the season.
Michigan State was ranked as the preseason No. 1 team in the country in Monday's AP poll, as the Spartans return three starters from a team that reached the Final Four. With Langford expected back in the fold, Izzo and the Spartans were favored to win the national championship.
With Langford out at least two months, however, Izzo will turn to sophomores Aaron Henry and Gabe Brown and senior Kyle Ahrens for perimeter production. Top-35 recruit Rocket Watts was expected to backup Wooden Award favorite Cassius Winston, but he could also see time alongside Winston in the backcourt.
Michigan State opens the season against No. 2 Kentucky in the Champions Classic at Madison Square Garden on Nov. 5.