Probably a scope which is just cleaning out fluid and removing excess scar tissue if so.
The biggest problem is with a acl is the mental aspect in addition to not being able to put any weight on the leg, you are incapable of putting any weight on your leg, if you try you just fall straight over unto the ground.
So there is a rust component, the mental component, the full rehab which can be between 12-24 to return to full efficientcy. You can't just say he has/had this so it takes x long. He has only been out for around 10 months so it is fairly early for him to be ready. He probably won't look back in form for a likely 5-6 months but the acl tear in football (usa) or hockey can take a bit. You can be recovered in around 12-13 months but to get full functionality can take up to 18-24 months. Luckily he didn't injure his mcl however. That takes longer but could be career ending.
ugh, your post made me curious and I had to go googling. It was major knee reconstruction including repairing an ACL tear. It said at least three months, and he came back nearly three months to the day, played 24 games averaging over 22 minutes a night and then nearly 20 minutes a night in the playoffs.
I'm not saying expectations should be the same for Svech. I've been saying for awhile that I expect him to start the year in GR. It's more that Chelly was just a freak.