49ers' 2025 outlook: Offensive ecosystem strong, D-line faces questions

The San Francisco 49ers underwent a significant roster overhaul this offseason, particularly on defense. That unit faces the most uncertainty entering the 2025 season, while the offense remains loaded with star talent.

Bleacher Report's Alex Ballentine recently analyzed each NFL team's greatest strength and biggest weakness for the upcoming season. For the 49ers, he emphasized that despite changes across the roster, the offense remains one of the league's most potent.

49ers' biggest strength: The offensive ecosystem

Ballentine identified the 49ers' offensive ecosystem as their greatest strength.

San Francisco locked up quarterback Brock Purdy with a five-year, $265 million contract extension in May, and Ballentine believes Purdy is an ideal fit for head coach Kyle Shanahan's system.

"But there's no denying it's the entire offensive ecosystem that drive the Niners' success," he wrote. "They've finished as a top-10 offense in five of the last six seasons under Shanahan's watch."

Ballentine believes Shanahan remains one of the NFL's premier offensive minds, and Purdy has no shortage of weapons at his disposal, including running back Christian McCaffrey and tight end George Kittle.

Wide receiver Brandon Aiyuk, still recovering from ACL and MCL injuries, is anticipated to return later, giving Purdy one of his top targets back.

"Even with Aiyuk set to miss some time early in the season, the Niners have the firepower to be dangerous," Ballentine added.

49ers' biggest weakness: Defensive line

On the other hand, Ballentine cited the defensive line as the team's biggest weakness following the offseason overhaul. San Francisco struggled to stop the run and generate consistent pressure on opposing quarterbacks last season, leading to the departures of veterans Javon Hargrave, Maliek Collins, and Leonard Floyd. The 49ers replaced them with rookies Mykel Williams, Alfred Collins, and CJ West.

"There was a time not too long ago when the Niners had the league's best defensive line," Ballentine wrote. "The last few seasons have chipped away at the depth they once had across the front four, though.

"Nick Bosa was a Pro Bowler last season, but he missed three games and underdelivered with nine sacks," Ballentine noted. "If he doesn't regain his dominant form, then this is a group without an established leader."

Ballentine emphasized that defensive coordinator Robert Saleh will need immediate production from Williams, the team's first-round pick, while the interior line remains largely unproven.

"Second-round pick Alfred Collins might wind up being their best interior defender," he wrote. "They could be surprisingly good, but the floor is low."

More from 49ers Webzone:

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• 49ers QB Brock Purdy and wife Jenna welcome first child!
• Kyle Shanahan cautiously optimistic about two 49ers rookies
• 49ers training camp: Pearsall, Purdy return; Observations from July 27 practice
• 49ers signing CB Eli Apple to a one-year deal