Efe Obada didn't know much about American football back when he first joined the NFL as an undrafted free agent back in 2015, and on Thursday he admitted that seven years into his career, there's still plenty for him to learn.

"It's forever changing," Obada said during a Zoom call with local and international reporters after signing a deal with the Washington Commanders. "I just try to continue my self-development so I can try to make myself valuable to a team."

As someone who didn't start playing the sport until his early 20s -- Obada was born in Nigeria and raised in the United Kingdom -- it's been important for the defensive end to have good teachers in his career. Between his stops with five teams, most recently the Buffalo Bills in 2021, he's had plenty.

Out of all of them, Obada's time with Ron Rivera and the Carolina Panthers has stuck out the most. He saw some of his most significant strides on the field being part of that culture, and it's one he's eager to dive back into with the Commanders.

"He's honestly the only person I want to play for," Obada said.

In his three seasons in Carolina, two of which were with Rivera, Obada played in 42 games with one start and recorded 62 tackles, 7.5 sacks, four pass breakups, two forced fumbles and an interception. His pick came during his first-career NFL game in 2018, and it helped him win NFC Player of the Week.

Those are some solid numbers for someone who was still learning the sport, but Obada's background makes them even more significant. He and his sister had a difficult childhood, as they were homeless when they first arrived in London and ended up living in 10 different foster homes.

Fast forward a few years later, and Obada was working as a security guard and playing as a tight end and defensive end for the London Warriors in the British American Football Association National Leagues, which is the highest level of American football in the United Kingdom. That led to a tryout for the Dallas Cowboys, who signed him to their roster a year later.

"My mindset is that of lack and coming from a place of being behind," Obada said. "I take pride in this, I know what this is ... My life has changed, my family's life has changed."

Obada bounced on and off the Cowboys' practice squad before signing with the Kansas City Chiefs in 2016. He was released and signed by the Atlanta Falcons later that year, only to be released again in August.

Obada was signed by Rivera and the Panthers the following year through the NFL's International Pathway Program. Per league rules, he was ineligible to be promoted to the 53-man roster for the season, and during that time he learned that the culture Rivera had established was unlike any he had been part of with other teams.

"It was that of learning, it was that of patience, that of growth, that of wanting to be better," Obada said. "Just how the coaches and Ron Rivera in particular carries himself as a man, it's something I've been around in terms of role models in men."

The players in Washington who have been around since Rivera became the Commanders' head coach in 2020 are familiar with the culture he brings with him. In addition to what Obada described, hard work and discipline are pillars that hold up his philosophy.

"The impact that he's had on my life, the opportunity that he gave me, the atmosphere and the ecosystem that he creates, it's just amazing," Obada said. "Being around the league and playing for different head coaches, I've never experienced nothing like it."

There's a high standard that comes with being part of a Rivera team, and Obada feels that has helped him develop and succeed with other teams. He showed that last year with the Bills, when he finished the 2021 season with 3.5 sacks and 12 tackles.

"If I dedicate my life and everything to this game that it's gonna pay dividends, and it has."

After two seasons of playing for different coaching staffs, Obada is ready to get back into Rivera's culture. Washington had expressed interest in adding him to their roster, and he was "adamant" there wasn't another team, or any coach for that matter, that he wanted to play for.

Now that the move is official, Obada has joined the Commanders talented defensive line led by Chase Young and Montez Sweat, who Obada said are "phenomenal" players. His focus is to help the team in any way possible.

"I'm going to bring some really great experience, I'm going to bring some really solid depth on the end," he said. "And then also, I'm going to be very impactful on passing downs. My philosophy is self-improvement and being impactful to the team."

Rivera gave Obada the opportunity to showcase his skills in Carolina, and it sounds like he's still grateful for that. Playing for the head coach felt like a good fit to him back then; it feels the same now, and he's ready to get to work.

"I felt like I should've made that decision earlier," Obada said. "I didn't want to make that same mistake."