Six players were absent from the 49ers' OTA practice on Thursday, according to the San Jose Mercury News.
Those not present were wide receiver Anquan Boldin, fullback Bruce Miller, offensive linemen Alex Boone and Anthony Davis, punter Andy Lee and kicker Phil Dawson.
OTA practices are voluntary and players are not required to attend.
Linebacker NaVorro Bowman was also not present though he was given the day off by 49ers coach Jim Tomsula. Bowman missed the 2014 season after sustaining an ACL tear during the 2013 playoffs.