During the offseason, two players are allowed to have duplicate numbers, so long as one plays on offense and the other plays on defense.
Below are the numbers being assigned to this year's undrafted free-agent rookies.
It's not noted above, but JaMycal Hasty, like Salvon Ahmed, is also a running back.
San Francisco announced the signings of nine of its undrafted free agents last month, and then later announced the signing of its tenth—running back Salvon Ahmed.
The 49ers last month announced the numbers for the team's five drafted rookies.