The wide open spaces in the 49ers’ zone coverage have resulted in some really long pass plays the past two weeks.

The 49ers lead the league in completions allowed of 20-plus yards (15) and 40-plus yards (5). Most of the deep damage has been done in back-to-back losses to the Steelers (43-18) and Cardinals (47-7) in which they’ve surrendered 676 passing yards and five touchdowns.

What’s going on here? Safety Eric Reid said the defensive backfield has been too slow to react and the defensive front hasn’t produced enough pressure. The 49ers have collected one sack and three quarterback hits in their past two games.

In other words, Pittsburgh’s Ben Roethlisberger and Arizona’s Carson Palmer have been able to calmly survey and locate the soft spots.

“That’s kind of the downside of the zone,” Reid said when asked about the openings in the secondary. “You’re not close to people. But we’ve got to a better job of breaking on the throw. A little better job of getting pressure on the quarterback, just so the quarterback isn’t so comfortable. Aaron Rodgers is obviously dangerous if he’s comfortable in the pocket, so that’s something we have to do this week.”

Yes, the 49ers will look to improve Sunday against Rodgers, a two-time NFL MVP who is playing better than at any point in his 11-year career, in the estimation of Packers head coach Mike McCarthy. Rodgers has become the second quarterback in NFL history to have 10 touchdowns and no interceptions in his first three games.

Rodgers acknowledged the 49ers are still in the figuring-it-out stage under first-year defensive coordinator Eric Mangini.

“We’re three weeks in, so a lot of teams are still figuring out the stuff they want to run and the stuff that’s working,” Rodgers said. “They’re whittling down their plans and continuing to add new stuff to the mix that they may have worked on in training camp. Teams are continuing to try to find their identity.”

For his part, Reid is confident the defense will get on the same page in a blitz-filled system designed to harass passers.

“You get pressure on a quarterback, you get him out the pocket, you hopefully get a sack and a turnover,” Reid said. “Force him into a bad throw.”

Is Reid confident the coaching staff is putting players in the best position to succeed?

“I’m very confident,” he said. “I love our scheme defensively. I don’t know much about the offense, but I’m sure the players love it over there, too.”

Twitter: @Eric_Branch