The Washington Football Team bolstered its linebacker corps by signing David Mayo on March 18.

A fifth-round pick in 2015, Mayo (6-foot-2, 240 pounds), has made 86 career appearances (19 starts) and recorded 173 total tackles (109 solo), eight tackles for loss and two sacks. Here are five things to know about Washington's newest defender.

1. He lived in a shed while making a name for himself at junior college.

Mayo was widely regarded as the best athlete to come through Scappoose High School in Oregon since former NFL quarterback Derek Anderson. As a senior, he averaged 10 tackles per game at linebacker and gobbled up 1,100 yards and 12 touchdowns as a running back.

Yet when he graduated in 2011, he had zero FBS scholarship offers.

Mayo still thought he could play at that level, so instead of committing to Portland State (FCS) or Western Oregon (Division II), he played at Santa Monica College in California, which has produced a slew of NFL players. Mayo was hellbent on proving himself, even if it meant living in a 10-by-15-foot shed.

"The price of living there is just insane, so I ended up finding a place that was in my price range," Mayo told the Carolina Panthers' team website in 2015. "It was $450 a month. I had a bed and this little ottoman thing for my clothes, and that was it. It had cement floors, wasn't insulated. I ran an extension cord from the house, so I could power up my computer and phone and a lamp and a heater in the winter."

Mayo was a productive starting linebacker in his lone season at Santa Monica College, but it also took some luck for him to accomplish his goal. Texas State was transitioning from FCS to FBS, giving it more than 30 scholarships to work with. The coaching staff took advantage by scouring every junior college in the country, and Mayo was one of the players that caught their eye.

"I liked him," then head coach Dennis Franchione told The Charlotte Observer in 2015. "He was upfront and honest. When David said it, you could take it to the bank and count on it."

2. Ron Rivera saw his NFL potential at Texas State.

Mayo was neither the biggest nor the fastest player on the field, but he was always around the ball when healthy. He immediately became a starter in 2012, then missed the second half of the season with a torn meniscus. The next year, he led the conference with six solo tackles per game before going down with a sprained MCL.

Mayo finally played in every game in 2014, which went a long way towards establishing himself as a potential NFL prospect. He finished third in the country in total tackles (153) and second in tackles per game (12.8) -- both of which made him a deserving choice for Sun Belt Defensive Player of the Year.

"He's smart. He's instinctive. He can run," then Panthers general manager Dave Gettleman told the team site in 2015. "He's got very good straight-line speed, and he will tag your fanny."

Mayo wasn't invited to the NFL Scouting Combine or any of the showcase games, but Gettleman, along with then Carolina head coach Ron Rivera, believed he would be a worthy addition to their defense. That led to the Panthers selecting him in the fifth round (169th overall) in the 2015 NFL Draft.

"[Texas State] did some interesting things with him," Rivera told told The Charlotte Observer in 2015. "They played Navy and that option of theirs and they lined him deep in the middle like a deep middle linebacker and you saw him flow one way or the other. He's got some natural feel as far as linebacker instincts, and he looks like he has some [strongside] linebacker ability as well."

Mayo is one of 43 Texas State players to become NFL draft picks -- a list that includes former Washington standout wide receiver Ricky Sanders. Mayo is one of three Bobcats currently in the league along with tackle Ty Nsekhe (Dallas Cowboys) and center Aaron Brewer (Tennessee Titans).

3. He spent his early years learning from a stellar linebacker group in Carolina.

In terms of his development, Mayo could not have asked for a better landing spot than the Carolina Panthers in 2015. His head coach played linebacker for nine seasons and coached the position for the better part of two decades, while his new teammate, Luke Kuechly, was coming off back-to-back first-team All-Pro seasons. Add in veteran tackling machine Thomas Davis Sr. and first-round pick Shaq Thompson, and Mayo had no choice but to meet their exceptional standards.

"Those guys are so good -- [Luke] and TD and Shaq -- and they prepare so well," Mayo told The Charlotte Observer in 2017. "I prepare with them and learn a lot from them because even though I may not be starting the game ...I can absorb all that as well."

Mayo only started four games during his four seasons there, but he was a standout special teams player and valuable defensive reserve who stepped up when necessary. In his final two years, he assumed the responsibility of backing up one of the best linebackers in football.

"Very, very comfortable with the way that David handled things," Rivera told the The Charlotte Observer in 2017 when Mayo was forced to replace Kuechly midgame. "Smart football player, physical guy, plays downhill, handles things very well."

4. He's shown he can be a capable starting linebacker.

Mayo's contributions with the Panthers earned him a two-year contract with the San Francisco 49ers in 2019, only to have the team let him go before final roster cuts.

The release turned out to be a positive for Mayo, who quickly caught on with the New York Giants and took over as one of the starting linebacker's in Week 4. He ended the year as one of the team's most productive defenders, finishing tied for second with 80 tackles (50 solo) to go along with five tackles for loss, two passes defensed, two sacks and a fumble recovery. A few months later, he parlayed those statistics into a three-year extension.

Mayo entered 2020 as the starter but suffered a torn meniscus before the regular season opener that landed him on Injured Reserve. By the time he returned in Week 6, he could not regain his spot. While he led the team with nine special teams tackles, he started just two games and recorded 20 tackles on defense. To free up cap space, the Giants released Mayo and Golden Tate in early March.

5. He's a prototypical Rivera signing.

Cultural fit, coaching fit and playing fit: those are the three areas Rivera looks at when deciding which players to add to the roster. Mayo checks all of these boxes.

Mayo is intelligent, physical, ambitious and willing to do whatever it takes to have success (see: living in a shed). He also played under Rivera for four seasons and went to a Super Bowl with him, so he knows exactly what Rivera expects both individually and collectively. He can pass along all of these insights to younger linebackers like Cole Holcomb and Khaleke Hudson.

Personnel wise, Mayo can orchestrate the defense as a middle linebacker or provide a sure tackler on the strong side of the formation. Playing behind a fearsome front, he should have plenty of chances to make plays from either spot.

Having lost Kevin Pierre-Louis during free agency, Washington could still make moves to address the position before training camp. But signing Mayo gives defensive coordinator Jack Del Rio with a hard-nosed, underappreciated player determined to reward Washington for giving him his latest opportunity.