Posted by ESPN.com's Tim Graham
PITTSBURGH -- Baltimore Ravens cornerback Frank Walker was escorted off the field with an unknown injury in the second quarter of Sunday's AFC championship game against the Pittsburgh Steelers.
Walker moved slowly from the sideline, flanked by two members of the Ravens' training staff.
Walker is listed on the depth chart as the backup for left corner Fabian Washington, but he started four games at right corner in October and November and started at left corner in the regular-season finale.
He had 33 tackles, one interception, two forced fumbles and 14 passes defensed.