Hall dislocated his ankle in October 2019 and in the process, broke his fibula (bone in the lower leg) and tore his deltoid ligament (which helps with ankle stability). He underwent surgery, and is expected to be ready to play in time for training camp (NFL players undergoing this surgery return to running and cutting by 6 months, according to one small study). Data from 42 players suggests a temporary decline in games played (by ~2) during the first year back, but return to baseline afterwards. No effect was seen on productivity. Therefore, we have low level of concern.
Image Source: Aaron Steele, CC BY-NC-ND 4.0