Adam Caplan of FOXSports is reporting that the Minnesota Vikings are expected to sign free agent cornerback Frank Walker. Walker had tryouts with the New Orleans Saints and the Tennessee Titans recently.

The Vikings are expected to place Cedric Griffin on injured reserve after he suffered a major knee injury last week. According to reports Griffin tore his ACL in his right knee. The Vikings are left with Asher Allen, Chris Cook, and Lito Sheppard.

Cook is likley out next week, as he is still recovering from surgery on his torn meniscus. Walker spent 2008 and 2009 with the Baltimore Ravens, who decided not to re-sign him after the season.