This 49ers rookie needs to start in the secondary vs. Lions

Rookie safety Ji'Ayir Brown needs to start for the 49ers as they take on the Lions.

Baltimore Ravens v San Francisco 49ers
Baltimore Ravens v San Francisco 49ers / Ryan Kang/GettyImages

12-5. 50. Sunday, Jan. 28. 49ers -7. Fox. 49ers-Lions opening. 12-5. 42. 6:30 p.m. ET

The San Francisco 49ers defense was not at its best against the Green Bay Packers in the divisional round of the NFL Playoffs. The Niners gave up big plays, were not able to sack Jordan Love, and had too many missed tackles.

However, they were able to stand up and force field goals on several occasions which was the difference in the game.

San Francisco's defensive unit is going to have to play better against the Detroit Lions in the NFC Championship game. The Lions have an impressive offensive group that features a great offensive line, weapons like wide receiver Amon-Ra St. Brown and Sam Laporta, two great running backs in David Montgomery and Jahmyr Gibbs, as well as a quarterback who is playing well in Jared Goff.

The 49ers have the talent to limit the impressive Lions offense, but it is a matter of going out and executing.

That could start with a lineup change in the secondary.

Most of the attention paid to the 49ers' secondary in the Green Bay game was focused on Ambry Thomas, who had a rough game at cornerback. He committed some obvious pass interferences that allowed the Packers to score. But his poor play overshadowed another potential weak link in the Niners secondary: safety Logan Ryan.

Ryan is a veteran who won a Super Bowl with the New England Patriots, so it is understandable why head coach Kyle Shanahan opted to start him over rookie Ji'Ayir Brown who was coming off of a knee injury.

Brown filled in after safety Talanoa Hufanga went down with an ACL tear and did a really solid job in the role. Ryan was brought in as depth and became needed once Brown got injured.

Ryan has done alright for the most part, but there were some key mistakes that he made that cost the 49ers against the Packers.

The video below is one example:

Ji'Ayir Brown needs to start in 49ers' secondary against Lions

Ryan is not the only one who missed a tackle on that play. But if he had been able to put Jones down when he had the chance, that would have prevented a big play.

All the players on defense for the 49ers are veterans, which is great in terms of experience. However, there were times when the Niners defense looked slow and sluggish in the game against the Packers. Part of that may have had to do with the rain, but San Francisco will need more energy against the Lions.

Starting a rookie like Brown, who will be amped to get his first start in the postseason, could be just the injection of energy that the 49ers need. Brown was disappointed that he didn't get to play against the Packers, but Shanahan said that he has looked good in practice and could factor into the team's plan this Sunday.

Brown could be just the spark the 49ers' defense needs to play to their full potential against the Lions in the NFC Championship game.

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