Ego Ferguson is out for the next four games.

Dennis Wierzbicki USA TODAY Sports

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.

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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.