Harbaugh told KNBR-AM in San Francisco about Gore's absence, the San Francisco Chronicle reported Saturday. Harbaugh also said that kicker David Akers and center Jonathan Goodwin would miss the offseason program, explaining that the three players do not live nearby and have commitments to their families.
Safety Dashon Goldson, who has yet to sign the franchise tag placed on him by the team, will not participate in the program either, Harbaugh said.
Gore, 28, is currently under contract through 2014 after receiving a three-year contract extension worth as much as $21 million last August.
The seven-year veteran played in all 16 games in 2011, making his third Pro Bowl after rushing for 1,211 yards and eight touchdowns.
The team agreed to let the 35-year-old Moss skip the workouts he negotiated a contract as a free-agent in March, Harbaugh told Comcast SportsNet Bay Area earlier this week. Harbaugh said Moss will report April 30.