Once a young teenager who played pickup games with friends in Winston-Salem, North Carolina, the 21-year-old Mexican American player was scintillating for Pachuca during their title run in the previous Apertura season. As a double-threat in both defense and attack, the left-back was fantastic in Los Tuzos' two-legged final against Toluca in October, providing a goal and much-needed interventions in the backline.
After a dominant 8-2 aggregate victory for Pachuca in which Isais played both games, the defender would go on to lift a trophy for the first time in his professional career. Weeks later in November, he was then included in a list of up-and-coming players who would travel to Qatar and serve as a "sparring" squad for Mexico's senior national team at the World Cup.
So far, 2023 has looked just as promising. In January, Isais recently turned heads with a long-range golazo during a 4-1 win over FC Juarez. And as an undisputed starter for Pachuca, he has continued to make progress, game in and game out, while also helping his side look like title contenders once again.
Looking ahead, it's only a matter of time before he becomes involved in the highly publicized national team push and pull between Mexico and the United States, although he hasn't committed to either yet.
As for his club future, European teams are beginning to keep tabs on him -- which isn't surprising considering Pachuca's track record (Erick Gutierrez at PSV Eindhoven, Hirving "Chucky" Lozano to Eindhoven and then Napoli) of producing top talent.
Providing Pachuca with versatility in defense and attack
Born in Brownwood, Texas, in 2001, Isais' family relocated to the Mexican town of San Francisco del Rincon in the state of Guanajuato, near the city of Leon.
It was there that Isais began to develop a love for the sport. Eventually earning a spot with Morelia's academy, he became a starter for their under-13 squad in 2014, but then he moved to the U.S. that same year. With relatives nearby and with better job prospects, his parents decided on North Carolina.
In those days, Isais maintained a connection to fútbol during breaks at school and on the streets in Winston-Salem.
"At recess, we all played a little bit of soccer and then afterwards I'd make friends. They'd be like, 'Come over, we're going to play a game near the neighborhood,'" he told ESPN. "That's how I still got in touch with the ball."
He attended a 2017 tournament for Alianza de Futbol, an organization that runs competitions in the U.S. to discover Latinx soccer players. At that event in Atlanta, Isais was noticed by then-Pachuca scout Rembert Vromant.
"I saw a very interesting physical profile. At that time he played as a left winger, but I managed to coach his last day [in Atlanta] and I put him in a match at several positions," Vromant said of Isais. "I put him as a holding midfielder, like [Erick Gutierrez], for example. He did well. We put him as a left wing, he did well. We put him as a lateral left back, he did well."
Vromant, born and raised in Belgium and now head of scouting for the Royal Belgian Football Association, was then a Mexico-based scout with Los Tuzos. Sent to the region by Club Brugge to scout talent across the Americas -- an appealing project due to having a Mexican girlfriend at the time -- Vromant eventually stayed in Mexico, later landing a job with Pachuca as the head of performance analysis and scouting in 2016.
Vromant was won over not only by Isais, but by his parents who were involved in his development and support as well. Speaking with Isais' family about a chance to join Los Tuzos, Vromant advised them to consider signing an offer. In all, 10 teams offered following the event but there was one clear choice.
"We sat together again with the family at the table the next day and they were still convinced that Pachuca was the option for him," Vromant said.
Next Liga MX player to make jump to Europe?
You don't need to look far to find a template for success at Pachuca. Under Vromant's watch from 2016 to 2021, 31 homegrown products were able to make professional debuts. Most notably, stars like Gutierrez and Lozano were given the right tools to fine-tune their skills, establish themselves as key national team figures for Mexico, and make the leap to European teams.
"It's the most forward-thinking club, they invest in finding the best youth players and developing them," Vromant said. "We invested a lot in scouts. At that time, we had, I think, 15 full-time scouts, so there's no other club in Mexico that did the same. Now, some clubs started copying that, some clubs did it with similar success, but I think Pachuca is still the standard."
The club has morphed into a well-oiled fútbol factory that is a part of a larger facility that supplies housing, player-specific meals, a university and much more to many of the country's best emerging names.
"It's kind of like a college over here. They have dorms, they have school, they give you food. They give you everything," Isais said, who joined the setup in 2018.
Still, Isais had plenty to work through and prove before becoming a first-team player. Stints at Pachuca's third-division squad, U17s and U20s, along with a loan at Leon, were hurdles that he leapt past in his path to Pachuca's senior team in 2022.
"Even when he wouldn't play, he wouldn't complain and was just trying to improve on every training session. That's what definitely makes him excel," Vromant said.
When Daniel Alonso Aceves was sent on loan with Real Oviedo in Spain last summer, Isais seamlessly stepped into the Pachuca XI while displaying his attacking prowess.
"Where I'm strong is going up with the ball," Isais said. "I'm very good at offense."
When watching the defender, his underlying talents as a former winger are pronounced. There's a confidence when he progresses with the ball, often looking for intelligent passes going forward, crosses and occasional dribbles past opponents. Defensively, his 6-foot frame gives him a solid foundation for holding off players and winning aerial duels.
There's room for improvement to take him to the next level, though.
"A bit more [work on] my positioning, I think I can make it better. That would make me a better player," Isais said.
Vromant agreed but was optimistic with the advances he has been making.
"For him, it's about acquiring those [defensive] skills that he might have lacked with training for a few years, but I think he's improving and he will continue to do so. ... He has the confidence of not only the coach but also of the whole structure. At Pachuca, he's at the right club to continue to develop.
"People I know here, in Europe, are following him."
Although he was careful to respond, often taking his time to consider his measured answers, there was a sense of enthusiasm from Isais when he began to discuss his future club career.
"That's part of my dream. That's where I'm going to see the best level of me, if I go," he said about playing in Europe. "That's why I started. I want to be playing with the big ones. We know it's all a process [though], and I gotta respect it."
A call-up with Mexico or the U.S.?
Amid the growing evidence and hype that Isais could be a Europe-bound player, it's easy to forget that process he has been on. Despite making his Liga MX debut with Leon in 2020, it wasn't until April of last year that he secured his first minutes with Pachuca's senior team. Since then, he has been a productive and dynamic part of their starting XI, but for just a little over half a year.
However, there's something undeniably special about the fullback that garnered the attention of Mexico before the 2022 World Cup. As part of that aforementioned "sparring" squad in Qatar, Isais gained valuable experience training with senior players.
"That was so nice, training with the first team and seeing how they train. You know, have them give you little assignments that you should do to get better," Isais said. Looking back at the experience, he also pointed out the effort that veteran defender Hector Moreno made to give him praise and guidance, noting that "[he] was one that gave me a lot of advice."
Does this mean a commitment to Mexico's national team, or would he be open to USMNT call-up?
"I'm not committed to anyone right now. I'm just focused on my club right now, doing things right. Whatever comes, I'll see what happens," he said, adding that U.S. Soccer "haven't talked to me or anything."
Nonetheless, that first appearance for either nation could soon emerge in a new World Cup cycle. With CONCACAF Nations League matches, the Gold Cup and friendlies on the horizon, 2023 could be the moment in which Isais adds to his already auspicious and bright start to his career.
No matter what happens, though, Vromant believes Isais' intriguing evolution will continue.
"I think one of his strengths is adaptability to new circumstances and his resilience. ... That's why Mauricio continues to improve because he's intelligent and he's trainable," Vromant said. "That's something that any coach in the world likes to have in a squad."