It almost made too much sense for both sides, and it would have been a homecoming of sorts for the player.

As to why it never materialized, only general managers Brandon Beane and Joe Hortiz know.

The Buffalo Bills, who rank 24th overall in sack rate (5.67%), could have beefed up their pass rush for the stretch run by trading for Los Angeles Chargers' veteran Khalil Mack.

For some reason, the winless Chargers decided to hold on to the 35-year-old Mack, who played collegiately for the University at Buffalo prior to being drafted at No. 5 overall in 2014.

In his 13th season, Mack remains a starter. The nine-time Pro Bowl selection has 3.0 sacks through eight games, which is more than Bills' free agent addition Bradley Chubb can say at this point in the season.

A trade that 'should have happened'

After the deadline passed, Sports Illustrated identified "five trades that should have happened, but didn't, at the deadline," and one of them was "Khalil Mack to the Bills."

From a Chargers' perspective, Mack was seemingly the ideal player to trade away for draft capital. The season is officially lost, and Los Angeles gets nothing by letting the aging Mack walk in free agency.

"Their [the Chargers'] most enticing trade chip was Khalil Mack, who is on just a one-year deal and is still producing at a high level in his age-35 season—as evidenced by his 22 tackles, five tackles for loss and three sacks to begin the year," said writer Mike Kadlick, who named Buffalo a sensible landing spot for Mack last month..

Furthermore, presuming the Chargers were willing at some point, it would have been a feasible move for the Bills to make.

With Mack playing on a one-year contract reportedly worth $18 million, the Bills could have found a way to tensing salary cap compliant, especially considering they just freed up an additional $5.3 million in space by performing a salary conversion with Dion Dawkins. As for trade capital, the Bills have three mid-round picks in the upcoming draft with an additional fourth-round compensatory selection likely.

"An intriguing landing spot for Mack would have been the Bills. Through nine weeks, Buffalo’s defense has logged the 11th-lowest pressure rate at 34.1% and the 11th-fewest sacks with 17. Adding Mack to a room alongside the lines of Greg Rousseau and Bradley Chubb would only help the Bills improve upon those numbers in their quest for the franchise’s first Super Bowl title," said Kadlick.

It's worth noting that Mack's 3.0 sacks this season are more than every Bills' edge rusher besides Greg Rousseau.

Current Bills' OLB

Greg Rousseau (8.0 sacks)

Bradley Chubb (1.5 sacks)

TJ Parker (1.5 sacks)

Javon Solomon (1.0 sack)

Michael Hoecht (0.5 sack)

Mike Danna (0 sacks)