SANTA CLARA -- Defensive coordinator Vic Fangio assigns equal blame to the 49ers’ pass rush and the coverage.
“You can’t play good pass defense in this league without a good pass rush,” Fangio said. “And they go hand in hand. You can’t have good pass rush without good coverage.”
The loss of outside linebacker Aldon Smith, serving a nine-game suspension, is glaring. Smith recorded 42 sacks in his first 43 NFL games. In the first three games this season, the 49ers have just four sacks. Justin Smith has supplied the only consistent pass rush with three sacks -- another wiped out due to a penalty.
The lack of a pass rush has forced Fangio to call more blitzes than usual. The 49ers sent more than four pass-rushers on 14 pass plays against the Arizona Cardinals last week, according to Pro Football Focus.
After not sending a defensive back at the quarterback in the first two games, safety Jimmie Ward blitzed seven times out of the slot position and cornerback Perrish Cox rushed the passer four times.
“We’ve had to call on it a little bit more lately here last week,” Fangio said. “Hope to not have to play that way all the time.”
Arizona quarterback Drew Stanton exploited a Ward pressure to find a favorable matchup of Michael Floyd against 49ers safety Antoine Bethea for a 36-yard completion in the first quarter.
Although Fangio said there have not been many problems with communication in the secondary, both passing touchdowns surrendered in the 23-14 loss to the Cardinals came on blown coverages.
On third-quarter touchdown passes to John Brown of 24 and 21 yards, it appeared as if safety Eric Reid and Ward were to blame, when actually the players who were out of position were Cox on the first play and Reid on the second.
“One time we just didn’t pick up the route correctly from one player’s position and the other time we didn’t stay deep enough long enough,” Fangio said.
The 49ers' pass defense ranks tied for 14th in the league, giving up 226.3 yards passing per game. Where the problems have shown up the most are on third downs. The 49ers' defense has allowed a league-worst 51.6 percent of third downs to be converted -- and that does not include eight more third downs converted via penalties.