The five-time Pro Bowl defensive end was available for Thursday's game against the Jacksonville Jaguars after sitting out the preseason opener.
Allen sat last week against Philadelphia because he missed practices with his wife having a baby.
Cornerback Tim Jennings was available after being sidelined by a quad strain, but the Bears held out safety Chris Conte even though he returned to practice this week after having shoulder surgery. Defensive end Willie Young, right tackle Jordan Mills (foot) and tight end Dante Rosario (calf) were unavailable.
The Jaguars were missing linebacker Paul Posluszny (bruised biceps).
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