English was flying for a mark in Thursday night's match against North Melbourne when Charlie Comben came across to spoil.
Comben landed on English's left leg and the Bulldogs star grabbed at his knee and hobbled off.
English, who has played just 15 games this season due to a previous injury in his right knee, suffered damage to his medial ligament and is set for an undetermined time on the sidelines.
"In the fourth quarter, an opposition player fell across the outside of Tim English's left knee," Bulldogs medical boss Chris Bell said in a statement.
"This mechanism has stressed the structures on the inside of his knee joint and damaged the medial ligament in his knee.
"It is the opposite knee to which he damaged the same ligament early in the 2026 season.
"Tim isn't expected to return to play within the remaining home and away season games.
"We will monitor Tim across the next two weeks to more accurately determine his return to play plan."
It leaves the Bulldogs the daunting prospect of taking on Melbourne's superstar skipper Max Gawn without their first-choice ruckman in the final round, while Carlton big man Marc Pittonet is also in form.
Bailey Dale (shoulder) will miss between one and three weeks, as will Connor Budarick (ankle).
The ninth-placed Bulldogs (48 points) can't drop out of the wildcard places but would need to win both games, improve their percentage and have other results go their way to reach the top six.
Carlton would jump ahead of the Dogs with a win this Sunday.
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