The Western Bulldogs will be without defensive duo Alex Keath and Ed Richards for this week’s clash with the Adelaide Crows.

Keath has been a significant contributor for the Bulldogs this season, playing every game.

However, the 29-year-old was subbed out of Saturday night’s win against Melbourne and will now miss up to a month of football.

“In the first quarter, Alex came to the bench with a hamstring injury,” head of sports medicine, Chris Bell, said.

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“Although low grade, I expect Alex to miss the next three to four games of footy.”

Richards will be unavailable this week after being concussed in the third quarter.

The 22-year-old has played four games in an interrupted season, after missing the first three months due to an ankle injury.

“Ed was involved in a contest where he clashed heads. This caused him to have some concussion symptoms,” Bell said.

“Ed has come in well today and we’ll work through a process in the next 10 days or so to determine his availability.”

The timeline has become clearer for experienced ruckman Stefan Martin, who continues to work his way back from a groin and hip issue.

Martin is on track to return to availability in the next 3-4 weeks.

Injury list

Lewis Young (ankle) – test
Ed Richards (concussion) – TBC
Adam Treloar (ankle) – 1-2 weeks
Louis Butler (calf) – 2-3 weeks
Lin Jong (hamstring) – 2-4 weeks
Ryan Gardner (shoulder) – 2-4 weeks
Alex Keath (hamstring) – 3-4 weeks
Stefan Martin (groin/hip) – 3-4 weeks
Toby McLean (knee) – season