You can but it's not always a good idea. A recent study of 19 high-level athletes with an ACL injury showed they could get back to training without surgery in four to 14 weeks. The minimium after ACL repair is 12 to 16 weeks and often longer.
The down side of bypassing the recommended ACL repair is well documented. Studies show joint instability after ACL rupture leads to meniscus problems. The meniscus functions to transmit loads through the joint and hold it stable.
Once the meniscus is impaired then the joint cartilage is overloaded and damaged. The next step is the release of enzymes that destroy the layer of bone underneath the cartilage. All of this leads to arthritis of the knee.