A deal is not imminent, however, and there is no timetable on reaching an agreement, Comcast SportsNet Bay Area's Matt Maiocco reported Monday.
A road-grader in the run game, Iupati was named first-team All-Pro in 2012.
2013 NFL Draft: Team needs
Our analysts examine each team's game plan entering the NFL draft, identifying biggest needs, potential fits and more. More ...
"In scouting, you live for those moments when you find someone that comes out at his position (who) isn't likely to come out for another five to 10 years," 49ers general manager Trent Baalke said last October. "I don't know that (Iupati) is a once-in-a-generation player, but he's certainly not an every-year guy. You just don't find men that big; that move that well; that are that powerful on a consistent basis year in and year out."