But the newly minted Orlando City SC goal ace has put himself on the MLS stage in no uncertain terms in the past couple of weeks, an Expansion Draft pick up from Philadelphia Union who has proved an inspired choice, notably in Saturday's 2-2 draw at Montreal Impact with a goal and an assist.
The 24-year-old is the "other" Brazilian in the Lions' lineup, a versatile attacking midfielder who has been thrust into the spotlight by a combination of injuries and international call-ups.
His road to prominence has been long and winding but, by contrast, his partnership with Kaká has been short, direct – and rewarding.
"It has been pretty crazy," Ribeiro said. "As a pro athlete, you try not to be star-struck, but it is hard in this case when you're playing alongside a guy who has won everything and who is not just a great player but a great person.
"With time, you do start to get used to it and you try to treat him as just another guy. But it is still Kaká, you know?"
That Brazilian kinship – Ribeiro was drafted out of Coastal Carolina and speaks perfect English but hails from Belo Horizonte and played for Cruzeiro as a teenager – has been enhanced by coach Adrian Heath, who deliberately put Ribeiro next to Kaká in the locker room.
"I think it was a bit surreal for him at first," Heath says. "With the esteem [Kaká] is held in Brazil, it's hard to play alongside someone you grew up idolizing.
"But the fact is they are both Brazilian, they speak the same language and they have a good understanding together. And Pedro has been great the last couple of weeks. I am a firm believer in that you get out of football what you put in, and he has definitely put a lot in."
Ribeiro has a good touch for a 6-foot-4 former center back, which was developed from years of playing futsal before being picked up by the Cruzeiro youth academy at 17. He trained with the team each morning and went to school in the afternoon, thanks to a scholarship with a private school where his dad was a teacher.
But then the team asked him to get serious about his soccer.
"Most youth teams in Brazil train twice a day and then they have school at night," Ribeiro explains. "The coaching director said I had to pick school or soccer but, for me, getting an education was more important so I quit playing soccer at 18.
"A lot of kids in Brazil see soccer as their only option in life, but I came from a middle-class family and, for them, education was No.1. I am very thankful for everything my parents did for me, as they gave me a great education. Sport was very important to me, but it was a second priority."
With a soccer career apparently curtailed, Ribeiro got on with his life, watching his idol Kaká from afar and playing only once a week with friends.
"Then one of my cousins opened a sports agency," he recalls. "He was looking to place students in colleges in the US and asked me to be his first player. I was just working and playing at weekends so I said, ‘Why not?'
"Once I got to the US, everything just took off for me."
Ribeiro was an instant hit with Coastal Carolina, scoring 31 goals and dishing out 26 assists in a stellar college career that culminated as a MAC Hermann Trophy semifinalist his senior year (among many other awards) before Philadelphia made him the 15th overall pick in the SuperDraft last year.
"I had an opportunity to go to the [MLS Player] Combine in 2014 and was lucky enough to get picked by Philadelphia," he said.
Ribeiro started only three games for the Union last season and was farmed out for experience to their USL affiliate, Harrisburg City Islanders, where he played against a soon-to-be MLS outfit on the lookout for new talent.
"Pedro definitely caught our eye," Heath admits. "He gave Rob Valentino, who was probably the best defender outside MLS, a torrid time, and he could do a bit of everything. He always looked like he had a goal or two in him, and he gives us a lot of options moving forward."
Philadelphia's loss has certainly been City's gain to date, and his budding partnership with Kaká is potentially one of the team's most welcome developments.
"I watched Kaká for Sao Paulo when he was 17, 18, and he just did some amazing things," Ribeiro confirms. "He is eight years older than me, but I followed his career when he went to Milan for the first time and then Real Madrid. I certainly never imagined he would be my teammate one day, and I count it as a huge privilege.
"We do have an advantage in sharing the same language and, on the field, we can discuss things in Portuguese, especially at free kicks and corner kicks, so we will continue to make use of that, I hope. And like I said, it's Kaká, you know?"