The 49ers are 4-9 and coming off a debilitating loss to the Cleveland Browns, a team the Bengals swept by a combined 68-13 margin this season. The Bengals are 10-3, are expected to win their division and on the way to a fifth-straight playoff berth.
The one thing both teams do have in common is injuries are mounting up that will lead to a host of key players for both teams sitting out this week.
Andy Dalton is the big headline-grabber for the Bengals as a fractured thumb will sideline him this week and probably for the rest of the regular season. With Dalton out, AJ McCarron will make his first NFL start this week after an up-and-down performance against Pittsburgh.
The Bengals may also be without star tight end Tyler Eifert this week after he left Sunday's loss with a concussion. Backup tight end Tyler Kroft and h-back Ryan Hewitt would be in line for more targets if Eifert is in fact ruled out.
On defense, the Bengals may be without two key starting defensive backs. George Iloka left Sunday's game with a groin injury that had been lingering for the previous two weeks. If he misses this Sunday's game, backup Shawn Williams will get the starting nod.
Adam Jones may also miss this week due to a foot injury that caused him to be inactive vs the Steelers. He's iffy at best to play in San Francisco, which means rookie Josh Shaw could be in line for the start.
Vontaze Burfict was in-and-out of the lineup Sunday due to a neck injury and concussion evaluations. Since it wasn't enough to actually take him out of the game, he should be able to play vs the 49ers, but it will be something to monitor.
On the 49ers side, they'll be without a host of players who were key starters to open the season. The most notable of the 49ers now inured players is quarterback Colin Kaepernick, who is now on I.R. due to shoulder surgery. Kaepernick took the NFL by storm early in his career and led the 49ers to two NFC Championships and a Super Bowl berth. However, Kaepernick regressed mightily over the past two years to the point he was benched earlier this season for Blaine Gabbert before going on I.R.
Another key 49er now on I.R. is Carlos Hyde. The second-year running back out of Ohio State opened the season with a 168-yard, two-score performance in the opener against the Vikings and looked poised for a breakout season. However, a foot injury has cost him much of the past two months, and the team opted to end his season this past week. With him out, Shaun Draughn will get the bulk of the carries.
Also possibly out this week will be starting tight end Vance McDonald. Now in his third NFL season, McDonald has caught 21 passes for 218 yards and two touchdowns this season as he's taken over the No. 1 tight end role after Vernon Davis was traded to Denver before the trade deadline. However, McDonald suffered a concussion last week that caused him to miss this past Sunday's loss to the Browns. If he's out this week, look for Garrett Celek to get the starting nod.
A name familiar to Bengals fans from his days in the AFC North likely won't be 100-percent this week. Wide receiver Torrey Smith is in his first year with the 49ers after spending the past four years in Baltimore. However, quarterback inconsistencies and toe and back injuries have limited Smith to 24 grabs for 546 yards and three scores.
This past week, Smith played only 27 of the team's 56 offensive snaps (48 percent) and finished with one catch for 17 yards in the loss at Cleveland. He was questionable to play going into the game with those injuries, and it looks like they'll be plaguing him again this week. If he's out, that means third-year man Quinton Patton will be getting more targets this week in addition to veteran starter Anquan Boldin, who leads the team with 51 catches for 617 yards and two scores.
Perhaps the biggest loss for the 49ers will be stud offensive guard Alex Boone. He left with a knee injury during the loss to the Browns in the third quarter when a linebacker collided with him. He's easily one of the team's best offensive players and someone who will be sorely missed against a stout Bengals defensive line. When Boone went out, Marcus Martin, who initially started much of his career at center, moved over to left guard to fill the void while Daniel Kilgore played at center. It has been revealed that Boone has an MCL sprain and won't play again this season.