Cornerback Richard Sherman
This should be pretty obvious. Cornerback Richard Sherman is coming back from an Achilles injury and will be making his 49ers debut, of course he’s a player to watch. But the actual reason to watch Sherman is to see how the 49ers secondary will have to play in the future.
The Seattle Seahawks’ Cover 3 scheme, which the 49ers run, was at its best because of the talent of Sherman and safety Earl Thomas. Fellow safety Kam Chancellor was critical to the defense, but the back end of the secondary was run by the former two.
When it functioned at its best, the Seahawks would essentially leave Sherman guarding an entire third of the field. From sideline to the hash marks, Sherman would take the receiver that entered there and shut him down. That allowed Thomas to help the other corner, who would be thrown at due to Sherman’s blanket coverage.
When Sherman couldn’t do that kind of shutdown coverage and Thomas got injured, the defense fell apart. Sherman would need some safety assistance, which was harder to give because Thomas, who is extremely talented at controlling sideline to sideline, was injured.
Both sides became extremely vulnerable.
The 49ers don’t have a Thomas at the back, but they do have a better second corner in Ahkello Witherspoon than the Seahawks did back then. If Sherman plays anywhere close to his former peak self, the Niners secondary will be set. It could then focus on helping Witherspoon, thus helping the entire secondary.
If Sherman struggles or needs a lot more safety help than normal, the 49ers secondary will be in bad shape.