[3] They couldn't always afford to eat three times a day, so they worked at a young age as vegetable sellers and as karagadors (porters).
[4] Encouraged by the mayor of Orani, who knew personally the coach of the Adamson Falcons (which was Kenneth Duremdes at the time), the twins decided to move to Manila.
[11] On the twins' 20th birthday, they won over the San Beda Red Lions, ensuring an 18–0 sweep of the elimination rounds and an automatic Finals appearance.
[14] In the preseason, Lyceum won the Philippine Collegiate Champions League (PCCL) title, with Jaycee winning Finals MVP.
In a win over the San Sebastian Stags, Jaycee contributed 17 points, six rebounds, three assists, and two steals as Lyceum won its 10th straight game of the season.
[23] In a rematch with EAC, he had 15 points, seven assists, and four steals as they made the Generals commit 38 turnovers for the Pirates' 12th straight win.
[24] The winning streak was snapped the following game as Lyceum lost in the elimination rounds for the first time since 2016 due to a buzzer-beating putback from Perpetual's Prince Eze.
[31] Season 95 saw CJ Perez and team captain MJ Ayaay leave Lyceum to turn pro, giving more responsibility to Marcelino.
[38] In a rematch against the Blazers, he scored 15 of his 22 points in the second half to lead the Pirates to their ninth win of the season.
[44] The Pirates officially claimed the second seed with a win over the JRU Heavy Bombers in which he had 23 points and five rebounds.
[54] In 2022, he and his twin brother, Jayvee debuted in the Maharlika Pilipinas Basketball League with the Zamboanga Family's Brand Sardines.
[57] He then scored 21 of his 26 points in the fourth quarter and overtime to lead his team to a come-from-behind win over Valenzuela XUR Homes Realty Inc.[58] He got the MVP award in that year's MPBL All-Star Game, scoring 19 points, seven assists, and three rebounds as he led the South All-Stars to the win.
[59] For leading Zamboanga to an 18–3 record, Marcelino won the league MVP award and was also named to the Mythical Team.
[60][61] In Game 1 of their first round series against the Muntinlupa Cagers, the Marcelino twins combined for 20 points, 10 rebounds, and 15 assists.
[62] Jaycee then delivered a triple-double in Game 2 with 24 points, 11 rebounds, 11 assists, plus six steals as they moved on to the division semis.
[75] In a win over the Rizal Golden Coolers, he scored a career-high 27 points to go along with his five rebounds and four assists as they raised their record to 12–3.
In Game 1 of their first round series against the Quezon Huskers, Marcelino almost put up a triple-double with 20 points, 10 rebounds, and seven assists to lead them to the win.
[80] In Game 1 of the division semifinals, he led with 18 points, eight rebounds, four assists and two steals, but also recorded six turnovers as they lost to the Bacoor City Strikers.
Marcelino scored 20 points, seven rebounds, six assists, and four steals in an 18-point comeback win over South Cotabato Warriors.