49ers’ Offensive Line Pursues Historic Start Against Cardinals

San Francisco 49ers vs. Arizona Cardinals: Playbook

Brock Purdy may be building an early dark-horse MVP case, but the quarterback might as well be running for president — he’s already being protected like one.

Purdy has barely touched the turf through two weeks. Once viewed as a potential liability, the 49ers’ offensive line has instead emerged as a candidate for the best unit in franchise history.

As San Francisco chases its fourth 3‑0 start since 2019 against the Arizona Cardinals on Sunday, the team will also try to keep its quarterback upright for a third consecutive game.

Thirty‑one NFL teams allowed at least one sack in Weeks 1 and 2; the average quarterback has been taken down 4.7 times. Purdy has been anything but average — and so have the five blockers in front of him.

Anchored by Trent Williams at left tackle, San Francisco is the only team yet to surrender a sack this season — a franchise first, as every previous 49ers team had allowed at least one by Week 2.

Left guard Connor Colby entered the season as a question mark, earning the starting nod only when he took the field for the opening drive in Week 1. He has more than held his own. Although Colby started six games as a rookie last year, coach Kyle Shanahan said the past two weeks have “probably been his two most consistent games.” Colby is responsible for just two of the 12 pressures the line has allowed, and the unit ranks second only to Indianapolis in Pro Football Focus’ pass‑blocking efficiency metric.

With a 2‑0 record, the 49ers have improved to 17‑4 under Shanahan when not allowing a sack. They now have a chance to enter even rarer air against the Cardinals.

Arizona’s defense ranked fourth‑from‑last in sacks last season, posting only 10 more than the league‑worst 49ers (20), and has finished in the bottom four in three of defensive coordinator Nick Rallis’ first four years. The trend continues in 2026: four sacks and a 21% pressure rate both sit in the bottom third of the league through two weeks. The Cardinals have blitzed on just 16.1% of snaps, the fourth‑lowest rate in the NFL.

All signs point to San Francisco extending its perfect protection streak. If the 49ers keep Purdy clean against Arizona, they would become only the eighth team since 1970 to open a season with three straight sack‑free games. Six of the previous seven reached the playoffs.

Four 49ers teams in the 1970s went three games without allowing a sack at some point during the season, but no team has done it since — nor has any extended the streak to four games. The all‑time record remains the 1988 Miami Dolphins, who went 12 straight games without a sack of Dan Marino. Purdy wears No. 13 because of Marino; it turns out that isn’t the only thing they have in common.

Marquee Matchup: TE Trey McBride vs. 49ers Linebackers

Raheem Morris has yet to scheme for a tight end of McBride’s caliber. The two‑time Pro Bowler and 2025 first‑team All‑Pro caused problems in Week 11 last year, hauling in 10 catches for 115 yards and a score, though he was primarily matched against Dee Winters, Nick Martin, and Curtis Robinson. This time he faces a far stiffer test in Fred Warner, Dre Greenlaw, and rookie Jaden Dugger. McBride led all tight ends with 4.6 yards after the catch last season; the Seahawks limited him to eight receptions for 41 yards (15 YAC) in their 31‑7 win last week.

The Score: 49ers 42, Cardinals 21

Seattle entered Arizona with its backup quarterback and shredded the Cardinals’ defense for 381 yards. Imagine what Brock Purdy and Kyle Shanahan can do with the 49ers’ offense firing on all cylinders. After bulldozing their first two opponents — and with the cross‑country season opener behind them — there are no excuses for San Francisco not to extend its red‑hot start with a third victory of 20‑plus points.

4 Downs

Keys to the game

THIRD DOWN: The 49ers had to wait until the second half to pull away from Miami because their offense saw only two possessions before halftime. They must improve at getting off the field so Purdy and company can get to work. Jacoby Brissett may not create many big plays, but he protects the ball — his career 1.4% interception rate is the lowest on record — so generating stops will be paramount.

FINISH DRIVES: Through two games, San Francisco has scored as many red‑zone touchdowns as Arizona has had red‑zone trips. Only one of the 49ers’ red‑zone visits hasn’t ended in a touchdown, the best rate in the NFL, while the Cardinals have settled for field goals on half their trips, a bottom‑10 figure. Conversely, San Francisco has allowed opponents inside its 20 five times but yielded just one touchdown.

GET CMC INVOLVED: As impressive as the 49ers’ dominant start has been without heavy reliance on Christian McCaffrey, the all‑purpose back is due for a breakout. McCaffrey has totaled 154 scrimmage yards while playing no more than 55.4% of offensive snaps in either game — his lowest consecutive‑game usage since joining the team — setting him up to explode against a Cardinals defense that allowed Seattle to rush for 162 yards last week.

‘MANAGE’ MIKE EVANS: Evans’ instant chemistry with Purdy has elevated the passing game, but the 33‑year‑old veteran left last Sunday’s game with a hip injury that Shanahan said the team must “manage” this week. If Evans sits, Purdy would be without four receivers from the start of camp, notably the one he has targeted for a 142.9 passer rating (9‑of‑10, 103 yards). Jacob Cowing, KhaDeral Hodge, and Jordan Watkins will be asked to step up. Evans could feast on Arizona’s secondary, or Deebo Samuel may need to rewind the clock and deliver a Jaxon Smith‑Njigba‑style performance.

Source link