Torn meniscus isn’t good news, but it’s not a “serious” injury. He’s already missed two weeks, and I suspect he will miss 2 more. The fact that he hasn’t had to have his knee scopes to clean up the meniscus suggests to me that it’s a minor tear.
I’ve torn the meniscus in both my knees throughout my sports career. One of them needed to be scoped. No biggie. Was back to full swagger in less than a month. No pain or swelling.