Miller suffered a groin injury during Saturday's preseason game against the Vikings, Pat Leonard of the New York Daily News reports.
Coach John Harbaugh said there "might be a situation there" regarding Miller's health. While there is no official timeline for the running back's return, Harbaugh's comments imply that he may need to miss significant time. If Miller does have a severe issue, he is a strong candidate for season-ending injured reserve, in which case the Giants would likely look to free agency to find another depth rusher for the remaining preseason games.