This was reported by RIA Novosti with reference to a friend of Grachevsky Vladimir Dolinsky. 

“Good condition, much better than it was.

Doctors say that it is better that there is no critical condition.

He told me that today he sat in bed for the first time.

It seems like he's on the mend, ”Dolinsky said.

On December 31, Grachevsky's wife, Ekaterina Belotserkovskaya, reported that his condition was serious, but stable.

On December 28, Grachevsky announced that due to the coronavirus, he would spend the New Year in the hospital.