ALAMEDA, Calif. — The Oakland Raiders are expected to sign another one-year lease to remain in Oakland in 2015, but long-term their future remains unclear and suddenly it is not a given that coach Tony Sparano is interim.

In the wake of a 26-24 win over the Buffalo Bills Sunday, it’s hard not to look at some of the young talent and believe there is a foundation in place for better things.

Oakland won its final three home games of the season under Tony Sparano. They came against Kansas City, San Francisco and Buffalo, all which had winning records and playoff aspirations yet found themselves pretty much outplayed on both sides of the ball.

Whether the home surge is enough for owner Mark Davis to bring Sparano back as head coach is anybody’s guess. He is believed to be intrigued with the idea of bringing in current 49ers coach Jim Harbaugh — a Raiders assistant in 2002 and 2003 — but it would likely come at a huge cost.

Sparano, at least, talks with his boss. Dennis Allen, who was fired four games into the season, almost never spoke with Davis, dealing directly with general manager Reggie McKenzie.

When Sparano took over on Sept. 29, he met with Davis and established a relationship in part because at Miami he seldom talked to owner Stephen Ross and dealt only with general manager Jeff Ireland.

“I’ve got great feedback from Mark,” Sparano said at his Monday news conference. “Any conversation he and I have is open and really honest about everything. He’s the owner, he’s the boss and I owe explanations when it goes well and when it doesn’t go well. It’s been good give and take. That’s the way I am … I intend to keep communicating with him for as long as I have.”

Harbaugh could command as much as $8 million per season — possibly more — and might want his own hand-picked general manager. In that scenario, Davis would be on the hook for paying Harbaugh, the new general manager and current general manager Reggie McKenzie for two more years. And because Harbaugh technically has a year left with the 49ers, he could cost something extra, such as a draft pick. The Raiders made such a deal with Tampa Bay when Jon Gruden went there from Oakland.

Former coach Allen is also in the books for one more year of guaranteed money.

With those kinds of mounting costs, and the Raiders responding well under Sparano, it’s not out of the question that if Harbaugh isn’t legitimately in the picture, Davis could opt for continuity and go with McKenzie and Sparano. And the idea of giving up a draft pick for a team that is building is, well, something to consider.

Sparano has dodged inquiries about extending his interim status beyond 2014.

Asked if he deserved a chance to continue, Sparano said, “Do I feel like it? Yes.”

Asked if he deserved it, Sparano said, “Do I deserve it? That’s not for me to decide.”

Sparano does believe putting together the three home wins against teams with winning records — the Raiders never beat a team with a winning record under Allen — counts for something.

“You guys write the story. I don’t write the story,” Sparano said. “We just do what we do out there on the field. But what it says to me is this team has bought in hook, line and sinker. And they’re in it for the long haul. And they fight. And they’re tough-minded guys.”

Whatever mistakes McKenzie has made in free agency and his first two drafts, he has appeared to hit the mother lode with last year’s draft class, getting both a possible franchise quarterback in second-round pick Derek Carr and a potential superstar defender in strong side linebacker Khalil Mack.

Carr is a game away from starting all 16 games in his rookie season and in relative good health despite his team’s 3-12 record. He’s outplayed all other rookies in his class. Mack could well be the NFL’ defensive rookie of the year and has been almost unblockable against the run and has also been a powerful pass rusher.

Add to that two other large pieces — 336-pound rookie guard Gabe Jackson and 350-pound nose tackle Justin Ellis — it’s hard to imagine any other rookie class being any better than what McKenzie brought to Oakland.

That doesn’t include sixth-round pick TJ Carrie, who has played extensively at cornerback.

It’s enough to make four-year veteran center Stefen Wisniewski hope for another contract with the Raiders despite all the losses.

“Obviously this is a business and I’ve got to make a business decision, but I love being a Raider and we’ll see what happens in free agency,” Wisniewski said. “There’s a lot of young talent and having Carr, a quarterback the team can believe in and rally behind, is huge.”

REPORT CARD VS. BILLS

–PASSING OFFENSE: B — Quarterback Carr completed 11 of his final 14 passing attempts after starting out 6-for-20, finishing 17 of 34 for 214 yards and two short touchdowns. He had a 51-yard pass to Andre Holmes and a 50-yard completion to Kenbrell Thompkins, both which set up touchdowns. Carr had zero interceptions and was sacked only once.

–RUSHING OFFENSE: B-plus — The NFL’s 32nd-ranked run defense had 140 yards on the ground — their second highest total of the season. The Raiders ran the ball more times than they passed it (36 to 34) for only the second time this season. Latavius Murray had 23 carries for 86 yards and Darren McFadden had his most effective game since October with 54 yards on nine attempts. Each had a 25-yard run.

–PASS DEFENSE: B — Don’t be deceived by Kyle Orton’s final numbers — 32 of 49 for 329 yards, three touchdowns. Charles Woodson and Brandian Ross had inteceptions and Orton’s timing with his receivers appeared off all day in large part because of the Raiders pressure. Khalil Mack had a sack and was a game-long presence in Orton’s face. Tellingly, Orton led the Bills on a final scoring drive while Mack was out with cramps. Justin Tuck also had a sack for the Raiders. Rookie Keith McGill had 48 snaps and held up well in coverage.

–RUSH DEFENSE: A — The first time the Bills tried to run C.J. Spiller, Antonio Smith dumped him for a 5-yard loss. Buffalo gained 13 yards on 13 carries and never had a gain of more than four yards. Middle linebacker Miles Burris led the Raiders with 13 tackles and the Oakland defensive front was often on the other side of the line, dominating the Bills offensive line.

–SPECIAL TEAMS: B-minus — Sebastian Janikowski converted field goal attempts of 45, 36, 38 and 49 yards before a miss from 48 late in the game. Coverage units, which have been subpar in recent weeks, were quite good against Buffalo. Marcus Thigpen had just 11 yards on three punt return and the only kickoff return of any distance was 27 yards by Thigpen. Punter Marquette King didn’t start off punting well, but finished with a 44.0 average and a 39.9 net.

–COACHING: A — Interim coach Tony Sparano said a third straight win at home with his team well out of the playoff race indicates the players have bought in “hook, line and sinker.” No denying since Nov. 9 this has been a well-prepared, emotional and motivated team at home. Offensive coordinator Greg Olson was able to be persistent with run and utilized the screen well to slow Buffalo’s charge. Orton never looked comfortable operating against Jason Tarver’s defense.