The Indianapolis Colts are feeling pretty good about themselves heading into Sunday's road game against the Oakland Raiders.

The Raiders (1-5), meanwhile, are coming off a dispiriting bye week in which another star player was traded away, leaving a cloud over the locker room.

The Colts (2-5) pulled off a dominant 37-5 home victory over the Buffalo Bills to end a four-game losing streak, and first-year head coach Frank Reich is amazed at how much that victory has raised the team's spirits.

"I shouldn't say it boggles my mind, but it really does," Reich said. "This is just an emotional game. Win or lose, the whole building feels it. So after a win, there definitely is more energy, there's a great vibe in meetings and in the building.

"So really we have to focus on, that's great, let's feed off that but still keep that same grit and determination that we're going to fight just as hard even though you have the positive vibe."

The return of tight end Jack Doyle to Wednesday's practice also lifted spirits. Doyle caught 80 passes last season when he was named to the Pro Bowl, but has played just two games this season because of a hip injury.

The presence of wide receiver T.Y. Hilton was noticeable against the Bills, as he returned after missing two games with a hamstring injury to catch two touchdown passes against the Bills.

Colts quarterback Andrew Luck threw four touchdown passes with no interceptions in that game, and his 20 TD passes for the season are second in the league, behind only Patrick Mahomes' 22.

Luck admits winning a game makes things run more smoothly the next week.

"Yeah, a little bit," Luck said. "I do think with Frank's leadership, it's been a steady building. Every week, it's been, 'OK, it doesn't matter what we did last week. We're now onto a new one-week cycle.'

"Certainly a win and a positive result maybe gives a little more confidence, but today, it's so what? Who cares? We're onto the next one. It's a tough trip to Oakland. Some guys on this team have done it before. Two years ago, we came back with a bad result (33-25 loss). So we know it's always tough out there. They're a team that's hungry. We're a team that's hungry. It will be a good match."

Indianapolis' offense has been productive all season. Luck has been sacked just 10 times this season and operates an offense that is 10th in the league in points scored at 27 per game. The Colts even added a running threat against the Bills, as Marlon Mack rushed for 126 yards and is averaging 6.1 yards per carry for the season.

The Colts' defense showed improvement against the Bills. They entered that game ranked 30th in total defense, but did not give up a touchdown to the Bills and forced five turnovers.

All this could be a problem for Oakland, which ranks 28th in the league in scoring offense, at 18.3 points per game, and 29th in scoring defense, at 29.3 points per game.

Plus the team has been enveloped in a shroud of uncertainty since preseason. Earlier they traded one of the league's best defensive players Khalil Mack, to Chicago. Then on Monday, they sent wide receiver Amari Cooper to the Dallas Cowboys for a first-round pick.

The Raiders have had an extra week to try to recover from their 27-3 loss to the Seattle Seahawks in London.

But it won't be easy. With Marshawn Lynch placed on injured reserve this week with a groin injury, it will place even more pressure on quarterback Derek Carr.

Carr has been sacked 17 times this season, and may be under more pressure against the Colts, who rank fourth in the NFL with 21 sacks.

The Oakland quarterback is aware that the Raiders' image is not the best at the moment in Jon Gruden's first year in his second stint as Oakland head coach.

Carr tweeted on Tuesday: "I'm a Raider. It's not a 'popular' thing to be a Raider right now, but I am and I love it. I love the struggle of trying to fight back for our city when not a lot of people believe in us. People can try all they want to tear us apart, but it's not happening to the real ones. (Skull emoji.)"

Raiders tight end Lee Smith also did his best to dismiss notions that Gruden had lost the team and that Carr was out of favor with his teammates.

"All these reports about this locker room being fractured with Derek Carr is the most obnoxious and ridiculous thing I've ever heard - ever," he said. "It's to the point where it's comical and laughable that I'm even sitting here talking about it. Us as players have zero issue with Derek Carr. ... Coach Gruden and Derek are going to take all the bullets. We're 1-5. We're not playing the football we want to play."

Doug Martin is expected to take over much of the ground-game workload with Lynch sidelined. Martin has just 97 yards on 27 carries this season. He did not have any rushing attempts against Seattle, and had two carries for 1 yard in the previous game against the Los Angeles Chargers.

Three seasons ago, with Tampa Bay, Martin rushed for 1,402 yards, but he is 29 now and the Raiders rank 24th in the league in rushing with an average of 92.5 yards a game.

The Raiders have another new kicker, Daniel Carlson. The most recent kicker to be dismissed was undrafted rookie Matt McCrane, who was signed in Week 4. In three weeks he missed four field goals and made touchbacks on only three of a dozen kickoff attempts.