The Oakland Raiders added two more key pieces to their defense on Friday.

During the day, the Raiders signed defensive lineman Antonio Smith and cornerback Tarell Brown. Smith was previously with the Texans and Brown the 49ers.

In 10 years, Smith has totaled 324 tackles (229 solo), 41.5 sacks, 10 forced fumbles, 11 fumble recoveries and nine passes defensed in 140 career games (117 starts).

Brown has 213 tackles (177 solo), 11 interceptions, 56 passes defensed and two fumble recoveries in 100 career games (47 starts).

Smith and Brown will join LaMarr Woodley and Justin Tuck on a defense that's looking to improve from its 22nd-ranked defense in 2013.

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Aaron Wilson covers the Ravens for The Baltimore Sun.