Defensive tackle Ego Ferguson was placed on IR in October because of knee injury

Otto Greule Jr Getty Images North America

LAKE FOREST, Ill. (AP) -- Bears defensive tackle Ego Ferguson became the second Chicago player in three days to be suspended four games for violating the NFL's policy on performance-enhancing substances.

Ferguson's punishment was announced Thursday, two days after backup offensive tackle Tayo Fabuluje was suspended. Fabuluje said in a statement he was informed he tested positive for an amphetamine after taking a supplement that did not list any banned substances on the label.

More from FoxSports

Ferguson was placed on injured reserve last month because of a knee injury. He appeared in four games with one start this season after playing in all 16 as a rookie in 2014. He will begin serving his suspension immediately.

The league also suspended practice squad receiver Jalen Saunders for an unspecified policy violation.

The Bears (3-5) visit St. Louis (4-4) this week.