Listen to RRoof, he’s a pro and has helped me go from a bad (low) ankle sprain the week before IMLP to IMMoo.
For me, a really bad sprain (I heard a “pop” but did not appear to severe the ligament) required 2 weeks off anything, then training with pool running for 2 weeks, then 3 weeks training on the road…with 2 weeks taper/off, I think it can race. I tried many braces and found the basic lace-up version, without the side support inserts to be the best. I can run fine with it and it helps the first degrees of stabilization best, which is what you need when you first get back on the road.
rroof knows his stuff