THE WESTERN Bulldogs will be without captain Bob Murphy for the next three or four weeks with hamstring and knee injuries.

With the 34-year-old injuring his hamstring in the win over S Kilda last Saturday, the club will take the opportunity to send Murphy into surgery to have a minor procedure on the knee he had reconstructed early in 2016.

Bulldogs medical services manager Chris Bell told westernbulldogs.com.au the veteran is likely to be sidelined for a month.

The Dogs face a tough month without the star playmaker, with clashes against Sydney, Melbourne and North Melbourne following this weekend's bye.

"Our assessment over the last 24 hours has confirmed that Bob has a moderate grade hamstring injury," Bell said.

"We're also going to use this time while he's in rehab to perform a quick arthroscopic cleanout on his knee, to address some of the minor signs of wear and tear he's had."

Forward Clay Smith, a late withdrawal from the clash with Saints, is expected to miss at least a fortnight with a minor calf strain.

In better news, the Dogs are hopeful veteran defender Matthew Boyd (shoulder) will be available to face the Swans next Friday night.

Youngsters Brad Lynch (hamstring) and Patrick Lipinski (collarbone) are likely to return through the VFL in two weeks.