Mangini’s new defense shows growing pains
On Wednesday, cornerback Dontae Johnson broadly spelled out how the 49ers’ system under defensive coordinator Eric Mangini differs from that of Mangini’s predecessor, Vic Fangio.
Three days later and 11 minutes deep into the debut of the new-look defense, it wasn’t clear what those guys were thinking.
In a 23-10 loss to the Texans in their preseason opener, the 49ers allowed 164 yards on the first 17 plays, which included a 58-yard touchdown pass, a 17-yard completion and runs of 32 and 14 yards.
Inside linebackers NaVorro Bowman and Michael Wilhoite, defensive tackle Darnell Dockett and outside linebacker Aaron Lynch didn’t play, and outside linebacker Ahmad Brooks and nose guard Ian Williams exited after the first series.
Starting inside linebacker Shayne Skov, who isn’t guaranteed to make the 53-man roster, was cleared out by a lead blocker on each occasion.
On Blue’s 32-yard run around left end, rookie outside linebacker Eli Harold, lined up at right defensive end, got sucked inside and fullback Jay Prosch led the way by nearly decleating Skov, who recovered to finish with eight tackles.
Cornerback Tramaine Brock, who began the play lined up inside against wideout Alan Bonner, raced over to cover Mumphery, but was way too tardy.
Earlier, on a 58-yard touchdown pass to Cecil Shorts from Brian Hoyer, Shorts wasn’t covered off the line of scrimmage.
On an extended goal-line stand, which was lengthened by a third-down pass-interference penalty, the Texans attempted six runs (five from the 1-yard line) and netted minus-3 yards.
Houston’s offense scored just 13 points in the final 54 minutes, but the Texans finished with 400 yards and their three quarterbacks — Hoyer, Mallett and Tom Savage — each posted a passer rating over 100.0, a first in the franchise’s preseason history.
[...] it’s essentially what Bowman said two days before the 49ers started off by struggling in Houston.