The Bombers’ coach fell off his bike while riding home from Essendon’s Tullamarine headquarters in wet conditions.
Hird’s head hit the ground and he suffered severe concussion as a result.
He was wearing a helmet which cushioned his fall and prevented further injury.
He was rushed to hospital and will spend the night under observation.
“James was very fortunate he was wearing a helmet which has braced his fall,” Club doctor Bruce Reid told the Essendon website.
‘’He has suffered severe concussion, however X-rays have cleared him of any fractures.”
“James will remain in hospital for ongoing observation and following a review we hope he will be discharged soon.”
The club will provide an update on Tuesday.