I thought he strained his meniscus but he was fine
I was (and still kind of am) worried about a hip flexor. He was grabbing his crotch after the fall
I've had a strain before, and other than the initial pop when it happened I didn't notice anything until I physically couldn't lift my leg into the car. If it's a minor one, I could totally see him playing through it until the adrenaline wears off.
Hopefully I'm wrong, though