APPLETON, WIS. -- Cornerback Frank Walker played for the Vikings on special teams in last Sunday's game against Dallas only days after signing.

It appears his role could be expanded tonight at Lambeau Field.

While rookie corner Chris Cook is expected to play versus Green Bay, Walker could see playing time in the nickel package if Cook has any issues with his injured knee. Cook has missed the past two games after having surgery to repair a torn meniscus in his left knee that he suffered on Sept. 26 against Detroit. There also could be concern because of wet field conditions at Lambeau.

Lito Sheppard played in the nickel last Sunday but he is listed as questionable because of a hand injury and it sounds as if the Vikings are not counting on him to play tonight.

Walker, 5-11, 194 pounds, spent the past two seasons with Baltimore but was not with a team before signing with the Vikings on Oct. 13.