ALAMEDA, Calif. -- In some parallel universe, the Oakland Raiders do not have Khalil Mack and Amari Cooper.

Rather, Sammy Watkins and Leonard Williams are donning the Silver and Black.

Don’t laugh. Because had the Buffalo Bills simply selected Mack out of the University of Buffalo (some 19 miles away from New Era Field) with the fourth overall pick of the 2014 draft, instead of Watkins, the Raiders would have been tempted to select the Clemson receiver one pick later.

And with Watkins in the fold, the Raiders would not have needed to draft a receiver a year later, as they did with Cooper at No. 4. Rather (and sans Mack), Oakland would have been in need of a pass-rushing defensive lineman who could also play well against the run. And that’s how they could have drafted USC’s Williams, who instead fell to the New York Jets at No. 6 that year.

The first domino, of course, was Buffalo passing on Mack and Raiders general manager Reggie McKenzie pouncing on him.

Two-plus years later, Mack is happy to be in Oakland, but he is again in a situation where he can make the Bills pay for ignoring him.

“I talk to Sammy about that every once in a while and tell him how he stole my city from me,” joked Mack, who also faced the Bills as a rookie and came away with a sack in the Raiders’ 26-24 victory. “But it’s going to be fun to [go] out there and play against them.”

Fun for Mack, who last weekend against the Carolina Panthers became the first player in the NFL since Charles Woodson in 2009 to record a sack, an interception for a touchdown, force a fumble and recover a fumble in the same game.

And hijinks for Woodson, whose text to Mack after the game went something like this, according to Mack.

Woodson: “Oh, word, that’s what you’re doing now?”

Mack: “Yeah, bro, that’s what you wanted me to do, right?”

Woodson: “Yeah, yeah, yeah, yeah.”

Not so much fun for the Bills, who have to scheme for the reigning AFC defensive player of the week, who ended Sunday’s 35-32 win over Carolina by beating a triple-team to strip-sack Cam Newton and recover the fumble.

“Him and Von Miller are the two best in the league right now, the two best edge pass-rushers and they can do it all,” Buffalo coach Rex Ryan said on a conference call with Bay Area reporters. “That’s what I’m seeing from him -- a guy that can play with speed, power, finesse. You name it, he’s got it.

“When you look at those two, they’re the only two, in my opinion, that are comparable.”

Mack has a team-leading nine sacks, with eight coming in the past six games. And after playing all 65 against the Panthers, Mack has played 622 of a possible 688 defensive snaps for the Raiders this season, per ESPN Stats & Information. On those snaps when he wasn't on the field, Oakland has zero sacks and just one takeaway, compared to 17 sacks and 16 takeaways with Mack on the field.

He is also one of two players, along with Buffalo’s Jerry Hughes, to have at least 300 snaps as a defensive end and 200 at linebacker, and Mack is one of six players with multiple sacks at both positions. (The others: Brian Orakpo, Frank Clark, Olivier Vernon, Markus Golden and Chandler Jones.) Seven of Mack’s sacks have come at defensive end and two at linebacker.

And Mack is the only player in league history to be named first-team All-Pro at two positions in the same season.

“He’s a monster,” said Bills outside linebacker Lorenzo Alexander, who played in Oakland last season. “I think everybody knows that. His game speaks for itself. There’s not too many guys that have his size, athleticism and passion and the work ethic for the game all within one person. That’s why he’s so dynamic.

“Obviously, if he continues to maintain his health, he’s going to be a Hall of Famer. He just continues to grow each and every year as far as understanding how to play the game of football from a mental standpoint.”

Raiders quarterback Derek Carr, a draft classmate of Mack, sees the same thing.

“He’s not a guy that just comes out here, shows up ... on Sunday and says, ‘Yeah, I’m just freakishly talented and I’m going to make all the plays,’ which he very well could,” Carr said. “But I think what separates him, and I think I’ve said it before, is his work ethic, the way he rushes the passer in practice. The way he chases down the run when it’s away from him at practice. And I think that that’s something that speaks louder than him just saying things with his voice.”

The Raiders move Mack all over the field, from left defensive end to the right end. From one outside linebacker spot to the other side. Hand in the dirt and standing up.

And he produces and wrecks games. Constantly. It’s just starting to show up on the stat sheet -- he had only one sack through the first five games -- but even early in the year he was affecting quarterbacks. The consistency is here now, in time for the Bills and their No. 1-ranked rushing attack coming to Oakland on Sunday.

“Just be disciplined and fundamentally sound,” Mack said of the Raiders' game plan against Buffalo. “Staying in gaps and getting off blocks and making it difficult for the running back to bounce around and create those seams. ... That’s the challenge.”

Imagine Buffalo’s challenge, then.

“It’s gratifying,” Mack said. “But at the same time we’ve got a lot of work to do.”

And for Oakland, perhaps to thank Buffalo for passing on Mack.