Jarencio hails from Sigma, Capiz, where his father, Benedicto Mariveles Jarencio, a civil engineer, ran a construction business.[2] He, along with his four siblings grew up in Project 3 in Quezon City.
His first sport was volleyball where he was once named Athlete of the Year while still in grade school. He attended high school at Quirino High School in Quezon City, where he began to play basketball.
He was a walk-in applicant for the Glowing Goldies after unsuccessfully trying out for Turo Valenzona's Trinity College team in the NCAA. He was able to secure a roster spot in UST, besting 200 other aspirants for a slot reserved for only four freshmen players.[3]
He is considered a journeyman, having played in six different teams in his 16 years in the PBA.[13] In his first six years, Jarencio had played as a reserve until he became part of the starting lineup in Ginebra.
Ironically, he was traded to Purefoods the following year and was again relegated to a reliever role, playing behind point guardsAl Solis and Dindo Pumaren. He was released to the expansion draft and was picked up by Pop Cola in the off-season. He became the second leading scorer for the team, behind Elmer Reyes, with a 12.1 point per game average in the 35 games that he played.[15]
Jarencio's break came when he joined Sonny Jaworski's team and became Ginebra's startingpoint guard.[16] He had been traded from Swift in 1992 and became the leading scorer for the team that season. He had an average of 18.6 points per game.[17] He scored 45 points against 7 Up, 44 against Swift and scored over 30 points in four other contests during the season.[18] He was awarded the PBA's Most Improved Player at the end of the season.
Jarencio was appointed head coach of the UST Growling Tigers on February 21, 2006. He replaced Nel Parado whose contract expired on February 15. Parado coached the Tigers for two years, and was only able to secure 4 wins in each season. [21]
In 2003, Jarencio had gone to UST to accompany his daughter in her enrollment and bumped into Institute of Physical Education and Athletics (IPEA) director Fr. Ermito de Sagon. Aric del Rosario had just resigned and the school was searching for their new head coach. Jarencio had no prior coaching experience so he declined Fr. de Sagon's invitation. Gina Francisco, the UST senior women's basketballteam captain when Jarencio was still playing for the Glowing Goldies, persisted in convincing him to apply for the head coach position. She referred him to UST athletics moderator Mike Silbor who arranged an interview with Fr. de Sagon. He passed the interviews and was later given a one-year contract with an understanding for him to rebuild the Growling Tigers' basketball program for the next three years.[22]
The Growling Tigers got into the UAAP finals two more times, in 2012, and in 2013, but they had not been successful in duplicating their feat in 2006. In eight seasons with Jarencio as coach, UST missed the final four on just two occasions, in 2008, and in 2010. The team also won the PCCL championship in 2012.
Jarencio resigned in 2013, at the end of UAAP Season 76, after failing to win the championship against La Salle. He had accepted an offer to coach a PBA team near the end of the first conference that year. He ended his eight-year coaching stint for the Tigers with an overall record of 56 wins against 54 losses in the elimination round, 10–8 in the postseason, highlighted by six final four and three finals appearances.
In game six of the 2006 Philippine Cup semifinals series between San Miguel and Red Bull, Guiao threw an elbow at San Miguel player Dondon Hontiveros, who was backing up in his direction after converting a three-point jump shot. Out of anger, Jarencio, charged towards the Red Bull bench and almost came into contact with Guiao, which happened in front of the referees.
Guiao was ejected from the game after incurring two technical fouls and was later handed down a one-game suspension and a P30,000 fine. Jarencio was called for one technical foul and was later meted a P50,000 fine for improper contact with an official and also a one-game suspension.[24]
In his first conference as GlobalPort coach, he posted a 1–8 win–loss record.[26] He ended his first season as a PBA coach with a 2–16 win–loss record.
He was fired towards the end of the 2014–15 PBA Philippine Cup despite doubling his win total in his first two conferences in the pro league at 4 wins and 5 losses. He remained with the team as a consultant.[27] On March 31, 2015, Jarencio was reappointed as the head coach of the Batang Pier.[28]
In 2013, it was reported that Jarencio will take over as coach of the Barako Bull Energy Boosters, but contract negotiations fell through.[29]
In January 2023, NorthPort named Jarencio as their team manager, replacing Bonnie Tan, who then became their interim head coach.[31]
On November 22, 2023, NorthPort lost 112–104 to the NLEX Road Warriors. During the game, NLEX import Thomas Robinson was involved in several collisions and had exchanged words with Jarencio in the third quarter. After the game, Jarencio and Robinson cursed each other in the tunnel. Jarencio then shouted "I'll shoot you later!" and had to be restrained by his players, security, and Commissioner Willie Marcial.[32][33] The next day, Jarencio apologized to Marcial and explained that he was carried away by his emotions. He also planned to apologize to Robinson.[34] A week later, the PBA imposed a ₱20,000 fine on Jarencio and gave him a warning. Meanwhile, Robinson's contract was terminated by NLEX citing "his taking an unplanned vacation and skipping team practices."[33]
