Bulldogs co-captain Frank Pritchard is facing three to four months on the sideline after suffering a pectoral injury in Sunday's 21-20 win over the Warriors.
Scans on Monday revealed Pritchard had torn his pectoral in the win.
The forward had made a comeback from an ankle injury in the match, but is now set to be unavailable for Canterbury until the late stages of the season.
The Bulldogs kick off Round 7 against the Rabbitohs on Friday afternoon at ANZ Stadium.