The Oakland defense still needs plenty more improvement, and both sides of the ball could do with fewer injuries.
After a morale-boosting performance in defeat against the New England Patriots last week, the winless Raiders looked porous from the start in Sunday's 38-14 loss to the Miami Dolphins at Wembley Stadium.
"Obviously, we did not play well," coach Dennis Allen said. "We turned the ball over; we did not stop them on defense. We gave up too many explosive plays."
The Raiders (0-4) started the game without linebackers Nick Roach and Sio Moore, who both were inactive, then lost Kaluka Maiava on the first series to a hamstring injury.
In the second half, it was quarterback Derek Carr who had to leave with ankle and knee injuries.
"I know the X-rays on his ankle were negative, but that's the extent of what I know," said Allen, who will be under intense pressure when he gets back to Oakland after the Raiders lost their 10th straight dating to last season.
The Raiders have a bye next week, and then host the San Diego Chargers on Oct. 12.
"We got a long flight back and we got a week off to evaluate everything that we're doing and see what we need to do moving forward to get better," Allen said.
Carr started Sunday's game on a high, completing a 30-yard pass to James Jones on the first play from scrimmage. A few minutes later, the Raiders took the lead when Carr hit Brian Leonhardt for a 3-yard touchdown.
Before he left, Carr was 16 for 25 for 146 yards. He also threw an interception.
Third-string quarterback Matt McGloin replaced Carr in the third quarter. Backup Matt Schaub did not make the trip to London.
On his second play, McGloin watched a bad snap fly by, and cornerback Cortland Finnegan ran it back 50 yards for a touchdown.
McGloin led the team on a 90-yard drive that ended with a 22-yard touchdown pass to Andre Holmes, but he also threw a pair of interceptions.
For the Dolphins (2-2), Ryan Tannehill led the way. The third-year quarterback completed 23 of 31 passes for 278 yards and two touchdowns despite being in the center of a storm all week because his coach declined to endorse him as the starter.
"I know I wasn't playing up to standards the last few weeks, so I wanted to come out and personally play better," Tannehill said. "My teammates demand that from me and they expect that from me, and to finally come out and do that felt good."
Tannehill threw a 13-yard touchdown pass to Mike Wallace and an 18-yarder to Dion Sims.
"I thought he had good rhythm. He had good tempo. He had good command. He was very decisive out there," Dolphins coach Joe Philbin said.
Note: Sunday's matchup was the first of three NFL games at Wembley this season. The Detroit Lions will face the Atlanta Falcons on Oct. 26, and the Dallas Cowboys will play the Jacksonville Jaguars on Nov. 9.
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