While MVP Patrick Mahomes and the new-look Chiefs were the talk of the NFL in 2018, the Chargers proved they too were a legit Super Bowl contender, as they split with Kansas City in the regular season, went 12-4, cruised against the Ravens in Baltimore in the first round of the playoffs before getting outclassed by the Patriots in the divisional round.

Rivers had his most efficient season in at least five years as a 37 year old, so there's no reason to expect Los Angeles to slow down in 2019, and yes, they will challenge the Chiefs for the AFC West crown. In fact, Rivers' 8.5 yards-per-attempt average was the highest he's had in a season since all the way back in 2010, which happened to cap a three-year run of him leading the league in that telling category. 

Because of Rivers' age, the Chargers' Super Bowl window is technically closer to being shut than wide open, but the NFL is a year-to-year league, and Los Angeles boasts a championship-caliber roster. Almost. 

Here are the three moves the Chargers should make between now and the start of the regular season to round out their depth.  

1. Sign another defensive tackle

In the back end of Round 1, the Chargers drafted Jerry Tillery, a tall, athletic, hand-work master with a high motor who's primed for a big rookie season between Melvin Ingram and Joey Bosa. Cortez Broughton, one of my favorite sleepers in the entire 2019 NFL Draft, was added at defensive tackle in Round 7. But the depth at that position is lacking.

Darius Philon is gone from 2018's squad, and he played 58.5% of the defensive snaps. He chipped in with 33 total tackles, four sacks and a forced fumble last year. Literally as I was writing this Monday, Los Angeles re-signed Damion Square, a defensive tackle who was on the field for 51.1% of the snaps in 2018 and registered 31 tackles, three quarterback takedowns, and three batted passes at the line. Obviously with Square back, this need isn't as massive as it was even a day ago, but it's still the most glaring need on this team.

Who could the Chargers sign immediately? Have to start with Ndamukong Suh.

The 32 year old has been waiting patiently on the free-agent market since March, and the likely reason he hasn't been signed yet is due to his monetary demands. While not the elite defender he once was, Suh proved he's still an upper-echelon defensive tackle in 2018 with the Rams while playing on a one-year, $14M deal. It's safe to assume he's demanding close to $10M per year. The Chargers have just under $13M in cap space for 2019 per OverTheCap.com but sit in 11th with $58M in space in 2020. So moving the money forward a year in a sizable deal for Suh would be the most logical way to get him on the roster while staying under the cap. How would that get done? A low salary coupled with a hefty-ish signing bonus spread out over multiple years of a contract.

For the time being, more reasonably, Danny Shelton who played admirably in mostly a run-stopping role on the Super Bowl champion Patriots in 2018, turns 26 in August and is still available. Caraun Reid, a 2014 fifth-round pick of the Lions who spent time with the Chargers in 2016, is on the market. While not as capable of generating splash plays like Shelton, he's more well-rounded. 

If none of those options come to fruition, the Chargers must be active on the veteran cap casualty market when it arises at the end of August before the season. Even if a newcomer takes a month or so to learn the system and find his exact niche on the team, that's fine, as long as that player is up to speed for the final stretch of the regular season and the playoffs. An idea here ... Gerald McCoy, who's decently likely to hit the open market at some point before the season, and he may be available via trade right now. He'd be a remarkable fit as a penetrating three-technique in Gus Bradley's system. 

2. Find offensive line depth or ... a possible starter?

I was hesitant to list this as the second-most pressing need for the Chargers, despite it being pretty obvious that a right side featuring big liabilities Dan Feeney and Sam Tevi is not going to cut it throughout the entire season. 

Yes, on paper, Los Angeles needs upgrades at those two spots. Then again, because of the Philip Rivers, the need isn't that big. 

For years now, Rivers has been among the top quarterbacks in getting rid of the football quickly, and, just as importantly, he routinely floats around the top 5-10 in passer rating under pressure. In fact, as of December 1 in 2018, his 92.0 passer rating while under pressure led the NFL, per PFF. That rating was higher than Jameis Winston's (90.2) and Matthew Stafford's (89.9) under any circumstance last season. Rivers epitomizes what it means for great quarterback to mask team flaws. 

Unfortunately for the Chargers, it's significantly easier for me to type "find offensive line depth or ... a possible starter" than it is for a team to do either of those things in free agency in May. Similar to the task to find at quality defensive lineman, Los Angeles may have to wait until deep into the summer to do so. 

With a glut of talented defensive backs -- which is a gigantic luxury in today's NFL -- could the Chargers move one of them in a trade for a starting right guard or tackle? Ehhh. Unlikely, but the idea needs to be mentioned because it'd make a decent amount of sense and the Chargers have a surplus of corners and safeties and a shortage of good blockers. 

3. Acquire a tertiary target at receiver

Mike Williams looked like a first-round pick in 2018 after a disappointing and injury-riddled rookie season. As an NFL sophomore, Williams led the team with 10 touchdowns and had the highest yards-per-target figure on the roster (10.1) among players with more than one catch. He did only catch 43 passes in the regular season though. There's room for growth. 

Keenan Allen is a reliable stud. He had more than double the amount of targets as the next-highest pass catcher on the team (136 to 66) and had 97 grabs for 1,196 yards with six scores. 

However Los Angeles didn't replace Tyrell Williams, who signed with the Raiders in free agency. He averaged a hefty 15.9 yards per grab on 41 receptions with five touchdowns. Hunter Henry could replicate that type of production in his return from injury. He won't be able to pose as serious of a downfield threat as Williams did though, obviously. 

Mike Wallace is still kickin', and while he's similar in size to Travis Benjamin, he is just two years removed from catching 52 passes at 14.4 yards per snag in Baltimore.

If the Chargers realize there's not someone with Williams' downfield ability on the market, they could lean toward even a more ball-control passing game which, really, would accentuate Rivers' quick-passing prowess. Someone like Jermaine Kearse, whom Bradley knows from Seattle, would be a sensible addition to the receiver group. Other options to fit this mold include Michael Crabtree, Pierre Garcon, reuniting with Dontrell Inman or Dez Bryant, anyone?