DENVER (AP) Even if he is ready, it's hard to think Peyton Manning would want to step in behind that offensive line.
Or throw to those slippery fingered receivers.
It might help that he won't have to worry about Khalil Mack, though.
More from FoxSports
The Broncos saw their already fickle quarterback situation thrown into more flux Sunday, courtesy of a suddenly revitalized rival in Oakland and a very good pass rusher in Mack.
The linebacker sacked Brock Osweiler five times, including one for a safety, and the Raiders snapped an eight-game losing streak against their AFC West foes with a 15-12 victory.
Now, instead of controlling their destiny for best record in the AFC, the Broncos (10-3) are a game behind New England, which beat Houston 27-6.
Oakland took care of the Broncos despite gaining only 126 yards, and though the loss could hardly be blamed on Manning's replacement, the easiest place to check for changes in Denver over the next few weeks will be under center.
''Still confident and great in the huddle,'' Broncos tight end Owen Daniels said of Osweiler. ''We have to play better around him.''
Manning, nursing an ailing left foot, is back to throwing. Asked if the five-time MVP would participate in practice this week, coach Gary Kubiak said Manning is ''moving forward'' with his rehab but ''I don't want to get too far ahead of myself.''
Osweiler led the Broncos inside the Oakland 20 three times in the first half but they didn't score a touchdown and settled for a 12-0 lead. Oakland (6-7) outscored the Broncos 15-0 in the second half. The Broncos haven't scored a touchdown in seven quarters.
Osweiler took responsibility.
''I wasn't making the right reads at times. I wasn't making the right throw at times. It culminated in a loss tonight,'' he said.
Still, there was plenty of blame to go around, starting with Denver's leaky line, which only produced 34 yards on the ground and allowed Mack to blow through for five sacks in the second half.
Osweiler's receivers weren't much better. Of the quarterback's 16 incompletions, at least a half-dozen were drops. One, by Demaryius Thomas, cost Denver a touchdown late in the first half. Thomas also lost a fumble. Another drop, by Vernon Davis, came on fourth-and-5 with less than 4 minutes left and nullified what would've been a 20-plus-yard gain.
Also, Oakland's go-ahead touchdown was set up by a muffed punt by Emmanuel Sanders at the Denver 11.
''A big-time mood swing,'' Sanders called it. ''I'll put this entire game on my back.''
Things we learned from Sunday's game:
THE MACK ATTACK: Mack's five sacks were the most in the NFL since 2012, when Aldon Smith had 5.5 for the 49ers. And they were the most by a Raider since Howie Long went for five against the Redskins in 1983 - the regular-season game that preceded their Super Bowl matchup.
''I didn't realize he actually had five sacks on the day,'' said Raiders coach Jack Del Rio, a winner in his first game back to Denver, where he served as defensive coordinator for three seasons. ''I knew he was awesome.''
GOING FOR 2: In one of the strangest coaching decisions of the season, Del Rio chose to go for 2 after a touchdown put the Raiders ahead 15-12 early in the fourth quarter. Carr threw incomplete and instead of needing a touchdown, the Broncos only needed a field goal to tie.
Del Rio explained that long snapper Jon Condo had hurt his right shoulder while recovering Sanders' fumbled punt. Given the choice between using the backup snapper and going for 2, Del Rio thought there was a better chance of making the 2-pointer.
''When that's the case, you have to use the information and have the courage to do the right thing for the team,'' Del Rio said.
CJ SITS: Broncos running back C.J. Anderson hurt his ankle last week. He was suited up but Kubiak said Anderson was available only in case of emergency. Apparently starter Ronnie Hillman's stat line - 12 rushes for 20 yards - wasn't considered emergency material.
''He should get better this week,'' Kubiak said of Anderson.
NO END ZONE: The Raiders finished the season without allowing Denver an offensive touchdown. Denver's only TD was Chris Harris' interception return in a 16-10 win in Oakland in Week 5.
Manning went 22 for 35 for 266 yards and two interceptions in the first game. Osweiler was 35 for 51 for 308 yards and no picks on Sunday.
''I believe it's the quarterback's job, no matter how the day is going, to get his team in the end zone,'' Osweiler said. ''I didn't do that today. I'll figure out a way to fix it and we'll move forward.''
AP NFL website: www.pro32.ap.org and http://twitter.com/AP-NFL