The Hawks released a statement on Monday afternoon detailing that the 19-year-old's condition was "initially quite severe" but has improved significantly over the last few days.
Hawthorn's club doctors have been in regular contact with the hospital and Anderson's condition is expected to improve but he will likely remain in hospital for the next week or two.
The club could not put a timeframe on Anderson's full recovery, however it is expected that he will return to the club in January.
Anderson played six matches in his debut season at the Hawks, including the qualifying final win over the Sydney Swans when he kicked a goal after coming on as the substitute.
