49ers lost to Titans simply because they couldn’t defend A.J. Brown

The 49ers made a plethora of mistakes Thursday night, but perhaps the biggest one of all was the inability to contain Titans wide receiver A.J. Brown.

Say what you want about San Francisco 49ers quarterback Jimmy Garoppolo having a bad game (he did).

But while he bears a lot of the blame for the Niners’ 20-17 Week 16 Thursday Night Football loss to the Tennessee Titans, the outcome would have been vastly different if San Francisco’s defense made the needed adjustments to cover fresh-off-injured-reserve Titans wide receiver A.J. Brown.

Brown would finish the game with 11 receptions, 145 receiving yards and one touchdown, his yardage alone accounted for over 60 percent of Tennessee’s receiving totals. The Titans were not hiding who they wanted to get the ball to after failing to run the ball with any success. Brown posted a career-high 16 targets with the next closest Titan only seeing three.

Cornerback Ambry Thomas made his third consecutive start for the 49ers, and the rookie surrendered Brown’s largest reception of the night which came on a 3rd-and-23. The 42-yard reception set up the Titans to take a late 17-10 lead coming off, yes, you guessed it, a Brown touchdown shortly thereafter.

Brown was activated from IR due to a chest injury he suffered in Week 11 and was on track to play all week, and for him to catch the Niners off guard is inexcusable.

Defensively, San Francisco did a great job containing Brown and the entire Titans offense in the first half, pitching a shutout en route to an early 10-0 lead. But disaster struck almost immediately as the second half began when Brown caught passes of 18 and 12 yards in a drive that resulted in Tennessee’s first points of the game.

A.J. Brown just gave opponents a template for beating 49ers

The 49ers secondary has been the weakest point of the defense all season long, and in Week 16, that was no different.

The Niners have consistently given up big-time performances to stud wide receivers this season with the Los Angeles Rams’ Cooper Kupp, the Green Bay Packers’ Davante Adams and the Cincinnati Bengals’ Tee Higgins each eclipsing 100 receiving yards. San Francisco’s young secondary will need to continue to grow if any sort of playoff push is on the horizon.

Read More: 49ers still have this major area of concern despite recent playoff surge

A problem, though, is the 49ers are running out of ways to cover up inexperienced players like Thomas, and opponents are making it a regular habit of targeting him, even though Thomas flashed some modest moments of promise and improvement since being pushed into a starter’s role three weeks ago.

Still, teams will look to exploit that weakness all game long for the rest of the regular season and especially in the playoffs moving forward.

Until the Niners can figure out how to account for their secondary, thereby eliminating the kind of performances like the one Brown showed Thursday night, it’ll remain a massive worry.