ALAMEDA, Calif. — After an offseason overhaul that brought on board veteran players with playoff pedigrees, the Oakland Raiders were optimistic for a turnaround after back-to-back four-win seasons.

After just two games, that optimism has quickly turned to frustration and disbelief as the Raiders have been physically dominated in losing to the New York Jets and Houston Texans.

With a trip to New England this week to face the Patriots followed by a “home” game in England against Miami, the Raiders (0-2) need to fix things quickly or the season could spiral out of control.

“We’re two weeks into the season. At the same time, you don’t want to bury your head in the sand,” coach Dennis Allen said Monday. “We’ve got to get better. We need to do it fast.”

The disappointment is already mounting with veteran safety Charles Woodson sounding off after the game, saying he was embarrassed by the team’s play and that the performance in the 30-14 loss to Houston “sucked.”

“I think that’s something that is spoken out of frustration,” Allen said. “When you watch Charles Woodson play in that game and the effort that he gave in that game and the passion in which he played in that game, it’s a tough pill to swallow. When you go out there and don’t perform like you’re capable of performing. He gave everything he had in that game and we have to get more guys playing like that.”

The biggest issues have been on run defense, where the Raiders have allowed an NFL-worst 400 yards rushing in just two weeks. They have been gashed by long runs from Chris Ivory in the opener and Arian Foster on Sunday and have consistently been beaten at the line of scrimmage despite the additions of Justin Tuck, LaMarr Woodley and Antonio Smith in the offseason.

The problems were especially bad at the start of the game when Foster had 12 carries for 76 yards on the first two drives as the Texans took a 14-0 lead.