The New England Patriots placed defensive lineman Sealver Siliga on injured reserve-designated to return with a foot injury.
They signed defensive lineman Casey Walker off the Carolina Panthers' practice squad.
Walker is a 6-foot-1, 340-pounder from Oklahoma.
At Oklahoma, he had 49 tackles, one sack, two forced fumbles, two fumble recoveries and two passes defensed.
Siliga has played in three games with two starts and has eight tackles.
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Aaron Wilson covers the Ravens for The Baltimore Sun