Throughout the offseason, we'll take a whirl around the AFC West to keep track of what the Chargers' rivals are up to.

Here's what went down over the last couple weeks since free agency began.

Denver Broncos

There's a new starting quarterback in the AFC West.

It was widely reported that Denver would be looking to upgrade their signal caller, and they announced shortly after free agency began that they signed QB Case Keenum to a two-year contract.  Keenum broke out in 2017 as he led the Minnesota Vikings to the NFC Championship Game.

Meanwhile, the Broncos traded their primary starter the past two seasons, Trevor Siemian, to Keenum's old team.  In return, the Vikings sent Denver a 2019 fifth-round selection while the Broncos also added in a 2018 seventh-round pick.

The Broncos were also part of one of the biggest blockbusters as they traded CB Aqib Talib to the Rams in exchange for a fifth-round pick.  Talib joined Denver in 2014 and made the Pro Bowl each season since his arrival.

Denver also saw a savvy vet leave them for the Bolts as TE Virgil Green inked a three-year deal to head west.  Green is regarded as one of the top blocking tight ends in the game.

In addition, Denver signed K Taylor Bertolet, CB Tremaine Brock, LS Christian Kuntz, DT Clinton McDonald in recent weeks while losing WR Cody Latimer, LB Corey Nelson and OT Donald Stephenson.

As far as re-signings go, the Broncos brought back LB Todd Davis and G Billy Turner.

Kansas City Chiefs

The beginning of free agency meant the Chiefs could officially announce a pair of trades that were widely reported on for weeks.

First, Kansas City announced they shipped QB Alex Smith to the Washington Redskins for CB Kendall Fuller and a 2018 third-round pick. The trade means that 2017 first-round pick Patrick Mahomes will take over under center for KC heading into next season.  He'll be backed up by Chad Henne as the former Jaguars and Dolphins QB inked a two-year deal with the Chiefs.

Meanwhile, the team also announced they traded Pro Bowl cornerback Marcus Peters and a 2018 sixth-round pick to the Rams for a 2018 fourth-round pick and 2019 second-round pick.  That means newly acquired Fuller will take over as the team's top corner alongside David Amerson, who signed with KC in February.

In terms of the Chiefs' free agent additions, the team made noise by inking WR Sammy Watkins.  The 6-2, 211-pound wideout has hauled in 192 passes for 3,052 yards and 25 touchdowns.  Another notable new face is LB Anthony Hitchens, who played in 60 games with 48 starts for the Dallas Cowboys since being drafted 119th overall in 2014.

So far, Kansas City has also signed RB Damien Williams and DT Xavier Williams while losing QB Tyler Bray, OL Zach Fulton, CB Terrance Mitchell, LB Kevin Pierre-Louis and WR Albert Wilson.

In terms of re-signings, the Chiefs brought back DT Stefan Charles, P Dustin Colquitt, OL Jordan Devey, DL Jarvis Jenkins, FB Anthony Sherman, LB Terrance Smith and WR De'Anthony Thomas.

Oakland Raiders

New head coach Jon Gruden wasted no time putting his mark on the team as the Raiders added more new players than any team in the AFC West.

Most notably, they signed Pro Bowl receiver Jordy Nelson, who is one of the top wideouts in Green Bay Packers history.  Nelson has career totals of 550 receptions for 7,848 yards and 69 touchdowns in 136 career games.  Another notable name is running back Doug Martin, who heads to Oakland after beginning his career with the Tampa Bay Buccaneers. The two-time Pro Bowler and 2014 first-round pick ranks fourth in Bucs' history with 4,633 rushing yards.

Meanwhile, the Bolts will face some familiar names in the secondary as a pair of former Chargers signed with the Raiders in S Marcus Gilchrist and CB Shareece Wright.  Oakland also welcomed WR Griff Whalen into the fold, who spent part of 2016 with the Chargers as well.

In addition, the Raiders also signed DL Tank Carradine, TE Derek Carrier, LS Andrew DePaola, T Breno Giacomini, QB Josh Johnson, LB Emmanuel Lamur, CB Rashaan Melvin, FB Keith Smith, P Colby Wadman, LB Tahir Whitehead and LB Kyle Wilber while losing DL Denico Autry, CB T.J. Carrie and WR Michael Crabtree. They also announced they were parting ways with longtime kicker Sebastian Janikowski.

Like the Broncos and Chiefs, the Raiders also executed a trade, sending FB Jamize Olawale and their sixth-round pick to Dallas for the Cowboys' fifth-round compensatory pick this year.

As far as re-signings go, they brought back DT Justin Ellis, QB EJ Manuel and TE Lee Smith.