Essendon defender Patrick Ambrose will have surgery on his wrist after suffering an injury during training on Friday. 

Ambrose, who has played 60 games for the club over the last four years, was set to secure his spot in Essendon's best 22 this season, however will have a delayed start to 2018 with his recovery time unknown at this stage. 

“Pat Ambrose fell on his outstretched hand during training on Friday. After getting scans today it was revealed that he has a fractured scaphoid in his wrist,” Essendon Physical Performance Manager Justin Crow said in a statement on the club's website. 

“Pat will have surgery to fix the issue on Tuesday and following the operation we expect to receive further clarification on what recovery time frame is required before he is available to return to play.”

Essendon's injury toll continues to mount on the eve of the season, with fellow defender Martin Gleeson and Orazio Fantasia also sidelined ahead of their round one clash with Adelaide at Etihad Stadium on Friday night.