ESPN's Adam Schefter says the workout will take place Monday.
The 49ers nearly ran out of healthy wideouts late last season. The position remains one of great need heading into the free-agent signing period, which begins Tuesday.
Michael Crabtree, Kyle Williams, Ted Ginn Jr., Josh Morgan, Braylon Edwards, Brett Swain and Joe Hastings were among the wide receivers Alex Smith targeted last season. Signing Edwards to a modest deal before the season showed a willingness to take on a higher-profile receiver.
Moss, who recently turned 35, is eligible to sign with any team before free agency. That is because he was not under contract to any team in 2011. He caught nine passes for New England, 13 for Minnesota and six for Tennessee during the 2010 season. He recently revealed intentions to come back for the 2012 season.
Moss does not appear to have strong ties to the 49ers' offensive staff. The 49ers' special-teams coordinator and assistant head coach, Brad Seely, provides one known connection. He and Moss were together in New England.
The 49ers could be interested in gathering information on all the available receivers before free agency begins. The workout could help give them a feel for Moss' expectations and physical condition.