Prosise, a third-round pick in last year’s draft, missed four of the previous five games with an ankle injury before returning to the field against the Cardinals last week. He left with an injury to his other ankle against Arizona.
Prosise played in five games, with 11 rushes for 23 yards and six catches for 87 yards.
The team also announced the previously reported signing of cornerback Byron Maxwell, officially placing cornerback Richard Sherman on injured reserve after rupturing his Achilles last week. Sherman is expected to undergo surgery this week.