A HAMSTRING injury will likely rule Essendon co-captain Steph Cain out for the entirety of the Bombers' finals campaign, with the winger expected to be sidelined for five to six weeks.

Cain suffered the injury during a training session on Tuesday. She had previously missed two games due to concussion.

“Steph had successfully returned from the concussion she suffered in round nine against West Coast and was back into full training,” the Bombers' head of medical services Megan Smith said.

“Unfortunately, she strained her hamstring in an innocuous incident at training and will now miss the next five-to-six weeks.”

Forward Daria Bannister has also undergone surgery for an ACL injury she sustained during round seven.

“Daria is in good spirits following her ACL surgery. We are in the process of managing the swelling and range of movement,” Smith said.

“This week, Daria will start to transition off crutches and progress into strength-based exercises.”

Alana Barba is also three to four weeks away from returning from a syndesmosis injury, with the midfielder increasing her running loads this week.

The finals campaign is the Bombers' first since joining the competition ahead of last season.