Citing a source, CNHI Sports Indiana's Terry Hutchens reported Wilson left the program because of an off-field issue.
ESPN.com's Mark Schlabach provided more insight regarding the reasons behind Wilson's departure:
"He was out about a week and they started a normal concussion regiment, in which he was allowed to work out for about 20 minutes and gradually increase it," the former player's father told Schlabach and ESPN's Chantel Jennings. "But after he worked out for 20 minutes, they had him run about six miles. After that, my son was feeling fine. But when he went home, he started throwing up and his symptoms went haywire."
Former Indiana center Gabe Ikard chimed in with his thoughts on Wilson shortly after the news broke:
Additionally, former Indiana player Laray Smith detailed some of Wilson's behavior and said, "Once you were hurt, he didn't care about you," per the Indiana Daily Student.
"Smith said he had an injury to his back during his freshman year," the Daily Student added. "The team told him it was just a bruise, but doctors told Smith he had a blood clot. Wilson still pressured Smith to play."
The Hoosiers made strides in the win column last season, when they went 6-7 and appeared in the Pinstripe Bowl, but they weren't able to improve on that total during the 2016 campaign despite starting the year 3-1. However, they did finish with a .500 record (6-6), which was good enough to make them bowl-eligible for the second year in a row.
Wilson's squad also flashed marked improvement on defense.
"From 2005-2015, the Hoosiers yielded 34.1 points per game," the Associated Press' Michael Marot wrote (via NCAA.com). "This year, it was down to 27.3. In 2015, Indiana was at or near the bottom in almost every major defensive category."
The timing of Wilson's departure was a bit puzzling at first glance since he inked a new six-year deal in January that was slated to pay out $2.55 million per year through the 2021 season, according to Zach Osterman of the Indianapolis Star.
According to Crawford, Wilson accepted $542,000 to walk away from the program. As a result, he left $12.2 million over five years on the table.
Now it will be up to defensive coordinator Tom Allen to lead the Hoosiers down a prosperous path after he was named head coach Thursday evening, according to a statement from the school.
"He is a leader of men," athletic director Fred Glass said in the statement. "He is demanding without being demeaning. He is a proven, successful coach on a national scale with deep Indiana ties. He cares about his players, and they care back."