The safety suffered a cardiac arrest and was resuscitated on the field.
He was rushed to the University of Cincinnati Medical Center, where he is said to have since been sedated on a ventilator.
As the NFL world has rallied around Hamlin, there have been positive updates from Hamlin's family regarding the 24-year-old's condition.
And the Bills offered more encouraging news on Wednesday in a post on their Twitter account.
It read: "Damar remains in the ICU in critical condition with signs of improvement noted yesterday [Tuesday] and overnight.
"He is expected to remain under intensive care as his health care team continues to monitor and treat him."