Barr (groin/hand) and Smith (knee/hamstring) were hurt in the first quarter Dec. 6 against Seattle. The Vikings also declared wide receiver Charles Johnson (ankle) and defensive end Scott Crichton (concussion/neck) out for their game Sunday against Chicago.
Defensive tackle Linval Joseph (foot) took part in practice Friday on a limited basis and was listed as questionable. He has missed the last two games. Defensive end Everson Griffen (shoulder) was also listed as questionable.
The other starting safety, Andrew Sendejo, was listed as probable and should be back after missing the last two games with a knee injury.
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