Okay before everyone in here has a meltdown:
I've torn both ACLs, had procedures and rehabbed both. Because of this, I've talked to countless doctors, therapists and read any medical journal I could find on the subject. BRACES DO ALMOST NOTHING TO PREVENT ACL TEARS. For someone who has normal muscle development(or beyond normal for an NFL athlete), the amount of force required and the type of force required cannot be stopped by any brace.
The majority of progressive surgeons/sports doctors at this point do not recommend braces, since if anything, they prevent the natural strengthening of the muscles that help stabilize the knee. Braces now are more or less to help the patient psychologically "trust" the knee again. If Davis doesn't feel the need to hesitate and second guess his knee, there is almost no advantage to wearing the brace. If Davis feels it's slowing him down(which is more then likely true but not to a huge degree), then he should most definitely take it off.