What is confirmed is Mayfield's absence from Thursday's practice. The starting assignment comes from beat and network reporting, not a formal injury designation, so Friday's final report is the official word on Mayfield's game status.
Coach Todd Bowles said when Mayfield got hurt that the thumb would cost at least three weeks, and ESPN reported a range of three to six weeks depending on his grip. Sunday would be the third game he misses.
Kickoff is 1 p.m. ET Sunday at Raymond James Stadium on CBS. Tampa Bay is 1-4. Pittsburgh is 3-2.
Daniels, an undrafted rookie, played his best game in Week 5. He completed 19 of 25 passes for 189 yards and a touchdown with no interceptions in the 24-16 Thursday night win at Dallas, and added seven carries for 23 yards. That was the Buccaneers' first win of the season.
The offense in that game ran through Bucky Irving. He carried 21 times for 165 yards and a touchdown and caught a second score, while Kenny Gainwell and Sean Tucker split the leftover work. With a rookie quarterback, expect that plan to hold against Pittsburgh.
For RSO owners, keep Mayfield on your bench or in an injured slot for one more week rather than cutting him. Sunday still falls inside the three-to-six-week window ESPN reported, so this is not a setback. Superflex teams short a quarterback can keep using Daniels, whose rushing gives him a floor. In one-quarterback leagues he stays a bench option.
Irving remains a locked-in start. Treat Emeka Egbuka, Chris Godwin and Cade Otton as matchup flexes while Daniels is under center.
Watch Friday's injury report for Mayfield's official designation and whether he returns to practice in any form. A limited session next week would be the first real sign he is close to taking the job back.