Bosa (calf) did not participate at the 49ers' practice Thursday, Nick Wagoner of ESPN.com reports.
Bosa was unable to practice for the second straight day to open the week as he continues to work his way back from a calf injury that has sidelined him since Week 2. The defensive lineman is all but guaranteed to miss a fifth straight game Sunday versus the Falcons, but the team expressed optimism that Bosa could return to action Nov. 8 against the Raiders, per Matt Zenitz of CBSSports.com.