According to an article in August, Tyler had:
- Anterior cruciate ligament (ACL): torn
- Lateral collateral ligament (LCL): torn
- Meniscus: torn
If you "just" tear an ACL, your recovery can be shorter, however it's dependent on what is used for the graft - cadaver, patellar tendon, hamstring (the latter two then result in healing time for that area).
If your LCL can heal on it's own, great. If not, then surgery complicates the recovery process.
If you tear your meniscus has to be repaired, then that's a bit of time immobilized before you are allowed to bend the knee, dependent on severity of tear, and if it was a remove or repair, where if just an ACL, they usually want movement fairly quickly.
I have been thru ACLs in both knees, and both times, was lucky to avoid the "terrible triad" of ACL/MCL/meniscus.
All this said, it's not surprising that he may not be 100%. Experts say that an ACL can take up to 2 years to heal from a whole body perspective - getting everything to talk to each other, proprioception, muscle rebuild, and the mental trust to do stuff without hesitating.