Two teams that seemed to be steamrolling toward a clash of unbeatens now find themselves looking to recover.

Although the Kansas City Chiefs and Buffalo Bills are each 4-1 and leading their respective divisions in the AFC, each will be coming off their first defeats Monday at Orchard Park, N.Y. The game got pushed back four days because of dominoes related to COVID-19 developments and kick off at 5 p.m. ET.

Each team allowed 40 points in their recent losses, creating deficits neither Patrick Mahomes nor Josh Allen could overcome quarterbacking the Chiefs and Bills, respectively.

Mahomes was constantly hounded and sacked three times by the Oakland Raiders in a 40-32 loss, leaving him to scurry quickly from the pocket and often look over the top in third-and-long situations.

"We can't just rely on the big play," said Mahomes, who completed a season-low 51.2 percent of his passes against Las Vegas. "We have to execute at a high level and when the big play comes, you have to hit it."

Although Mahomes often clicks on those looks, the end of a 13-game winning streak -- including playoffs, highlighted by last season's Super Bowl victory -- proved he is mortal.

Now, Mahomes must move on from a setback without experienced receiver Sammy Watkins (hamstring) and guard Kelechi Osemele (knee).

"I can help with different calls and putting people in better positions," Chiefs coach Andy Reid said. "Everyone has a little piece of the pie here."

That includes the Kansas City defense, which permitted 20 points or less in each of the Chiefs' first four games before allowing 490 yards to the Raiders, including five chunk plays of 40-plus yards.

Botched execution hurt the Bills in their first defeat and now they have a short week to recover after falling to Tennessee, 42-16, on Tuesday. Two interceptions and long returns Buffalo gave up on special teams proved fatal against a virus-plagued opponent that had practiced only once in 12 days.

One of Allen's interceptions bounded off the hands of a receiver, but the Bills quarterback will still be looking to rebound against the Chiefs. That will be a collective effort, though, after his defense could only get him the ball twice in the final 17 minutes against Tennessee.

Allen relies on one of the NFL's hottest receivers, Stephon Diggs, who ranks second in the league with 509 receiving yards. Allen, meanwhile, ranks second in passing yards (1,589) and touchdown strikes (14).

Those impressive numbers also present a concern, however. The Bills have become one-dimensional, gaining just 469 yards on the ground to rank 28th in rushing after ranking eighth in the NFL last season.

"The number of opportunities, run versus pass, has been a little bit different," Buffalo coach Sean McDermott said. "So, that would be one piece. Then the other piece is making sure that we're staying true to our philosophy in terms of what we're doing up front. It's a mentality."

Ground opportunities could exist against the Chiefs, who rank 29th against the rush, allowing 157.6 yards per game. Allen, however, is focused on overall execution.

"We're not going to let this one loss define us," he said. "We've got to be better, we've got to be prepared and we've got to come out swinging early."

The Chiefs' ground game (13th overall, 119.3 rush yards per game) looks like it will soon get a boost as former New York Jets and Pittsburgh Steelers running back Le'Veon Bell tweeted Thursday afternoon that he has joined Kansas City -- news that the Chiefs seemed to confirm with a subsequent tweet. The Jets cut Bell, a three-time Pro Bowl selection, Tuesday as the former three-time 1,000-yard rusher currently has just 19 carries and 74 yards in two games this season.

Bell will not be available to play Monday due to coronavirus-testing protocols, according to ESPN.

Buffalo wide receiver John Brown (knee) and cornerback Tre'Davious White (back) resumed light workouts after missing Tuesday's loss to Tennessee. Tight end Dawson Knox is dealing with a calf injury.

--Field Level Media