Flacco (shoulder) was spotted on the field at practice Thursday, Ben Baby of ESPN.com reports.
Per Baby, Flacco -- who didn't practice Wednesday -- was seen throwing ahead of the team stretch Thursday, but the extent of his participation won't be known until Cincinnati releases its second Week 9 injury report later in the day. Head coach Zac Taylor previously told Geoff Hobson of the Bengals' official site Wednesday that Flacco was "50-50" to play in Sunday's game against the Bears while he tends to an AC joint sprain in his throwing shoulder, but the veteran quarterback's outlook could improve if he fares well during Thursday's session.