That number shrunk to one after Davis said Thursday he plans on showing up.
Boone, however, does not plan to attend the three-day minicamp without a new contract.
NFL Media Insider Ian Rapoport reported, according to a source informed of the situation, that that the undrafted guard out of Ohio State won't report because it's the only leverage he has in trying to pry a new contract from the 49ers.
ProFootballTalk first reported the news.
The 27-year-old guard has skipped all of the 49ers' offseason workouts in hopes of upping his salary with two year left on his deal. As of now, he's set to earn $2 million with a roster bonus of $200,000 in 2014. His salary drops to $1.2 million in 2015.
Boone started 38 straight games the past two seasons during the 49ers' deep playoff runs.
Unlike Davis, being an undrafted player means Boone hasn't yet had his big payday, and he hopes to show his worth by withholding his services. He can be fined almost $70,000 for skipping all three days of next week's session, an amount he's willing to surrender to earn leverage.
Even with Colin Kaepernick signed to a team-friendly deal, the 49ers have other important contracts to consider for players who will be free agents sooner than Boone -- i.e. wide receiver Michael Crabtree. So even skipping minicamp might not earn Boone what he wants.