San Francisco's linebackers grabbed the top spot in analyst Seth Galina's ranking.
"It's hard to overstate Fred Warner's effect on the 49ers' defense in their run to the NFC championship in 2021," wrote Galina. "Amid replacement-level cornerback and safety play at times, Warner's gravitas over the middle of the field allowed the team to play a high percentage of zone coverage to protect its outside cornerbacks. His elite run-stopping ability was on display against the Packers in the divisional round, too."
Warner recorded a career-high and team-leading 137 tackles, seven tackles for a loss, three quarterback hits, four passes defensed, one forced fumble, and 0.5 sacks last season, per Pro Football Reference. The third-round pick in the 2018 NFL Draft is preparing to enter his fifth NFL season after recording career-high run-defense (73.6) and tackling (73.2) grades this past season. His 75.2 overall grade was his career's second-highest (88.6 in 2020).
"Warner had a transformative effect on the 49ers defense when he became the starter," wrote Pro Football Focus analyst Sam Monson in May. "And even though he hasn't quite been able to maintain an elite level of play every season, his impact on the field is obvious."
While fourth-year linebacker Dre Greenlaw recorded a career-high overall Pro Football Focus grade (69.5) in 2021, he only appeared in three regular-season games due to a lingering groin injury suffered in Week 1. The injury lingered for so long that it still affected Greenlaw even as the team was preparing to face the Los Angeles Rams in the NFC title game.
"Shoot, I still feel it," Greenlaw said, leading to that matchup. "Everybody's got injuries, but I still feel it now."
Greenlaw's presence heading into the 2022 season provides San Francisco with a good duo at linebacker.
"After missing most of the regular season, Dre Greenlaw came back for the end of the regular season and playoffs to form the perfect linebacker tandem with Warner," wrote Galina.
The 49ers also have Azeez Al-Shaair, who came in at No. 20 in that May ranking of NFL linebackers. He was the only 49ers player other than Warner represented on the list. Al-Shaair started in 13 games, recording a career-high overall Pro Football Focus grade of 64.8.