By around 8 years old, McKenna "Mak" Whitham knew she wanted to be a professional soccer player. What she probably didn't know is how soon that dream would become a reality.

Whitham, who turns 14 on Saturday, has signed a professional contract with NJ/NY Gotham FC, the reigning National Women's Soccer League champions, making her the youngest signing in NWSL history.

"I processed it, and it's still new to me," Whitham said about the achievement, in an exclusive interview with ESPN. "But, I mean, I'm not going to be cocky about it. I'm going to stay humble, and I'm still going to keep developing. My goal is to be a top player in the NWSL, and I know that Gotham will help me become that player."

Whitham's guaranteed contract runs through 2028 and will become effective on Jan. 1, 2025.

Whitham's pro debut, however, could come Sunday, one day after her 14th birthday. Gotham has signed her as a United States national team replacement player for Sunday's game against the Washington Spirit in the NWSL x Liga MX Femenil Summer Cup.

If she plays Sunday, she will also become the youngest player to ever feature in a first-division men's or women's soccer match in the United States. She would also be younger than any player who has appeared in the NBA, NHL, NFL, WNBA or Major League Baseball since at least 1970, according to the Elias Sports Bureau.

Earlier this month, 14-year-old Cavan Sullivan broke Freddy Adu's longstanding record as the youngest player to feature for an MLS side when he debuted for the Philadelphia Union. Whitham is about one year and 10 months younger than Sullivan. Second-division side Sacramento Republic signed a 13-year-old last year.

Whitham lives in Southern California but has been training with Gotham on and off throughout 2024. Gotham FC general manager Yael Averbuch West told ESPN the club has been measured in its approach to developing a 13-year-old alongside a professional team that features six players on the USWNT's Olympic roster, among other stars.

"The on-the-field is the easiest part of this, I think, and the quickest for us to kind of evaluate and know how to support her," Averbuch West told ESPN. "But we've undertaken a really robust process in terms of making sure that this is the right thing in her life, socially, mentally and every in every possible way."

Gotham heard about Whitham through its scouting network -- a combination of full-time scouts and industry contacts -- and invited her to join the team in Florida for preseason. Whitham immediately impressed and carried on with the team to Colombia for a preseason tournament in February.

There, as a non-roster invitee, Whitham scored the lone goal in a 1-0 victory over Colombia's Deportivo Cali. Gotham advanced and won the tournament.

Whitham was already making a name for herself by that point. In February, she became the youngest athlete in any sport to sign a name, image and likeness (NIL) deal with Nike.

The decision for Whitham to begin her guaranteed contract in January was part of a calculated process to not rush her, Averbuch West said. Whitham will have opportunities to get a taste of the professional environment during the NWSL x Liga MX Summer Cup, which pits teams from the U.S. and Mexico against each other.

"She's going to still be with us through this year and be able to train and continue to develop, and then kind of step up into the environment come preseason to fight for her opportunity on our roster," Averbuch West said. "We felt like that was the most appropriate progression."

Averbuch West describes Whitham as an athletic goal-scorer who covers a lot of ground on the field.

Whitham signed with Gotham through the NWSL's under-18 entry mechanism, which allows teams to sign up to four players under age 18 without having to go through the league's draft to acquire them.

Averbuch West said that the requirements for the U18 mechanism, which was introduced last year, have expanded to include additional provisions around pediatric medical evaluations, facilities and safety assessments (U18 players must have a separate locker room), and a long-term development plan as a player and a person.

U18 players are also required to live with a parent or guardian in the NWSL team's market.

That all means clubs must be ready for the responsibilities, too. The NWSL is less than two years removed from a pair of investigations that uncovered systemic abuse throughout the league. Deep reforms have followed, and rules on the entry of minors have simultaneously relaxed. There are now over a dozen teenagers playing the league, several of them in starting roles.

"We have spent a long time not just evaluating Mak as a player, but actually also evaluating our ability to support Mak and to create a safe and fulfilling environment for her," Averbuch West said.

"I mean, most important to any of this is that Mak continues to deepen her love of the game and her desire to get better. And so, we have done a lot of reflection. We've had a lot of conversations on our ability to support her in that and to create that environment for her at Gotham."

Whitham will move to the New York/New Jersey area with her mom, dad and 7-year-old sister soon. For now, she said, they will cherish what little they have left of beach time in California. She will continue homeschooling, as she has for several years.

Whitham's dad, Josh, was a member of the U.S. Olympic ski team in the late '90s and ranked as high as No. 40 in the world. He was an alternate at the 1998 Nagano Games as a high schooler.

"He understands it," Whitham said of her dad. "I mean, he's hard on me, but I appreciate it, because I would rather have that type of person to be hard on me than someone who just lets me, I don't know, go out, stay late, and I just think that he understands where I'm at, and I appreciate everything that he's done."

Averbuch West, who is a former player in the NWSL and was the founding executive director of the NWSL Players Association, stressed that Gotham is focused on Whitham's long-term future.

Sunday's Gotham game against the Washington Spirit, a top NWSL opponent, could be the next step in Whitham's development. The match, which could mark her official pro debut, will be played at Subaru Park in Chester, Pennsylvania, the home of the Philadelphia Union and the site of Sullivan's record-setting MLS appearance earlier this month.

Whenever the moment comes, Whitham will be living the professional dream she started planning for only a few years ago.

"I'd seen myself as a really good player, but also, there's a lot to improve on, and I knew that I could accomplish it," Whitham said. "And I think that it's a lot of hard work, self-belief."