The moves on Saturday come a day after Saints running backs Pierre Thomas, who has a shoulder injury, and Khiry Robinson, who has a forearm injury, were ruled out for Sunday night's home game against the Green Bay Packers.
Both Thomas and Robinson were hurt during New Orleans' 24-23 loss at Detroit last weekend.
Baker is a third-year pro out of Michigan State who was drafted by San Diego in 2012 and spent part of last season with Cleveland. He will be one of three active Saints running backs on Sunday night, along with Mark Ingram and third-year pro Travaris Cadet.
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