Beads of sweat ran down Thomas Rawls' face Sunday afternoon as he stood at his locker following the Seattle Seahawks' 38-7 win over the Minnesota Vikings.

The rookie running back was showered and changed, fresh off a 19-carry, 101-yard performance when he was asked for details about a phone conversation he had with head coach Pete Carroll in early May.

"I do remember him saying, ‘It’s not going to be given. You’re going to earn it,'" Rawls recalled. "I said, ‘That’s all I ever did in my life, coach.’ I said, ‘I just need an opportunity.’ And that’s what he did. He gave me an opportunity."

Added Carroll, "I told him that I’d personally watched him, and he was my favorite guy to get because of his style of running. We talked a little bit about Marshawn [Lynch] and his style. He knew of us and watched us play a little bit. ... I went back to my recruiting days. I was working hard."

Rawls' measurables (5-9/215/4.65) were not overly impressive. He had one really good year of college production at Central Michigan after transferring from Michigan. There were some legal and academic concerns, as well. And on draft weekend, Rawls didn't hear his name called.

Seven months later, he's proving to be one of the more productive running backs in the NFL. Filling in for an injured Lynch, Rawls is 10th in the league in rushing (786 yards) and second in yards per carry (5.57). According to ESPN Stats & Information, he leads all backs in average yards after contact (2.67) and is playing a key role on one of the hottest teams in the NFC. Yet 22 running backs were selected last spring, while Rawls was left to find a team in the hours after the last name was called.

He is one of 24 undrafted players on the Seahawks. Not all were original selections by Seattle, but that's 47.1 percent of the overall roster and the highest number in the league, according to the Elias Sports Bureau. The Seahawks are currently carrying 51 players, with two roster spots open.

The team credits its success to two factors. One, general manager John Schneider and his staff have invested time and resources into the rookie free-agent market. And two, Carroll and his staff have been willing to play guys who prove their worth.

"They take great care in looking deep into the ranks of the guys who are available," Carroll said of Schneider and his staff. "We never stop competing to figure out during the season who we can bring in that might have a chance to better our roster. And we’re more than willing to give those guys a chance. We’re really wide open to those guys and how they can contribute. We’d be crazy to think otherwise after the success we’ve had with guys."

A couple of years ago, the Seahawks started sending out a 12-page packet to agents. Eight of the pages contained graphs and data, showing how much preseason playing time each team gives to its undrafted guys, how many were on each NFL roster, how many were eventually signed to the practice squad and more.

Right tackle Garry Gilliam, who has started 11 games this season, remembers making his decision during the 2014 draft weekend.

"Toward the end there, I had a bunch of teams calling me, saying they wanted me to come on their team," he said. "The Seahawks were very, very persistent with their efforts to get me here. They probably called literally every five minutes."

Once it was Carroll. Another time it was Schneider. And Gilliam also heard from offensive line coach Tom Cable.

According to league rules, contracts are not supposed to be negotiated or signed until after the draft. But it's not uncommon for teams to have off-the-record agreements in place before the draft even begins. And once the final day arrives, targeting and recruiting undrafted free agents becomes a priority.

While the Seahawks emphasize opportunity, other teams use different tactics. According to one agent, certain organizations emphasize income tax advantages in their states to show how a player will be able to make more money.

Financially, there are limits. According to a league source, each team had a pool of $86,957 in 2015 to use on signing bonuses for undrafted free agents. But there are no restrictions on how much of a player's base salary can be guaranteed. Teams can use that option to make their offers more enticing.

The Seahawks believe they have an edge with results. When they took the field Sunday, seven of 22 starters -- Rawls, wide receiver Doug Baldwin, wide receiver Jermaine Kearse, Gilliam, center Patrick Lewis, defensive lineman Michael Bennett and cornerback DeShawn Shead -- were undrafted free agents. Players confirmed that the team uses those examples in its recruiting pitches.

"That’s legit," Gilliam said. "It’s not just them talking because you see Kearse, Doug [Baldwin]. Sherm [Richard Sherman] was late. Russell [Wilson] was late. [J.R.] Sweezy was late. All those guys, late-round draft picks or undrafted, all got opportunities to play. And they’re all starting now."

Carroll said he finds the type of player who goes undrafted to be attractive.

"We have a good history and background, so we’re hopeful that these guys are going to come through. We give them a chance," he said. "A lot of these guys that come through that course to get into the league, they’ve got an attitude about them. They know they’ve got something to prove. This game isn’t all about talent. So much of it is about your heart and how hard you’re willing to work and how you fight through all of it and the passion that your bring. Those guys, we really appreciate those kind of guys."

The Seahawks have had to offer up big paydays to players like Lynch, Wilson, Sherman, safeties Earl Thomas and Kam Chancellor, along with linebackers Bobby Wagner and K.J. Wright. They've signed or traded for players like Bennett, Cliff Avril and tight end Jimmy Graham.

There's no shortage of high-priced superstars on this roster. Given the salary cap, that makes undrafted free agents even more valuable. Rawls, for example, is making a base salary of $435,000 this season. He received a $15,000 signing bonus in the spring, according to a league source, which is the only guarantee in his 3-year, $1.59 million contract.

"Yeah, ultimately it is important," Carroll said. "With the kind of makeup that we have on our roster, it is important. That’s not something we’ve done to adapt to that, but it just happens to fit OK."