SANTA CLARA – Quarterback AJ McCarron put in a full day of work on Tuesday, the Cincinnati Bengals' off day, to prepare for his first NFL start.

The second-year pro from Alabama arrived at the Bengals’ practice facility at 9am and remained there until 6:15pm. He watched film and began studying for the 49ers, along with injured starter Andy Dalton and Keith Wenning, who was just promoted from the practice squad.

And his first impression is that the 49ers’ defense will provide a stiff challenge Sunday at Levi’s Stadium, where that unit has played much better than on the road.

“They play great at home, especially,” McCarron said on a conference call Wednesday with Bay Area reporters. “They’ve played everybody tough at home. They’re athletic, for sure. I feel like their D-line gets after it.

“They have a skilled group, for sure. It’s going to be a challenge for us.”

The Bengals (10-3) own a two-game lead over the Pittsburgh Steelers in the AFC North with three games to play, so Sunday’s game is important for playoff positioning. Also, it’s not known when Dalton will be available in the postseason after sustaining a fractured thumb on his throwing hand, so a first-round bye in the playoffs could prove especially beneficial.

It’s a big game for the Bengals, but McCarron is no stranger to the national stage despite his limited pro experience after being a fifth-round draft pick.

McCarron became the first quarterback to win back-to-back consensus national championships after Nick Saban’s Alabama team defeated Notre Dame in the 2013 BCS National Championship game.

 

“It doesn’t hurt, for sure,” McCarron said. “We played in a lot of big games when I was in college. A lot of pressure moments. But the way I’m looking at it is college is different than the NFL. It’s a totally different mindset for me. Just going in, preparing all week the best way I can, and knowing everything possible, and when it comes to Sunday, just got to go out and play the game.”

McCarron got the most extensive playing time of his career on Sunday. He completed 22 of 32 passes for 280 yards with two touchdowns and two interceptions in the Bengals’ 33-20 loss to the Steelers.