Rawls, 22, was filling in for Marshawn Lynch, who has been out with an abdominal injury. He signed on with the Seahawks as an undrafted free agent out of Central Michigan back in May.
This season, Rawls has appeared in 12 games and ran for 786 yards on 141 carries (5.6 YPC) to go along with nine receptions for 76 yards receiving and five total touchdowns.
Brown, 24, is a former seventh round pick of the Eagles back in 2012. However, he lasted less than two years in Philadelphia before he was traded to the Bills. Buffalo ultimately waived Brown a few weeks into the regular season.
The Seahawks wound up signing Brown to a contract over to a month ago, before releasing him at the end of November.
In 2014, Brown played in seven games while totaling 126 yards on 36 carries (3.5 YPC) to go along with 16 receptions for 176 yards receiving.