The story wasn't that Jack needed microfracture this offseason, the story was that he would need it within the next few years.
Jack himself stated, “[The degenerative problems are] there, but it’s nothing extreme,” Jack said at an NFL event for prospects at Grant Park. “Down the line, possibly I could have microfracture surgery — potentially. Who knows what will happen?
“Nobody knows how long anybody is going to play in this league. To play three years in this league would be above average.”
http://nypost.com/2016/04/27/myles-j...bout-his-knee/