Son of Sandra and Alfonso, and has three siblings: Sandra, Santiago and Angel...his sister, Sandra, played soccer at San Diego Christian College....Born on the side of Interstate 805 in San Diego on the way to hospital after his mother went into labor in Tijuana. ...Family lived in Tijuana before moving to Chula Vista, Calif., when Alfonso was in the fourth grade....Graduated from La Jolla Country Day (CA) before attending the University of Arizona....At UA, Rivas hit .323 with 15 homers during his collegiate career...as a freshman in 2016, he appeared in 55 games, making 47 starts in the field and 18 appearances as a relief pitcher, recording two saves during the Wildcats’ run to the CWS championship series....He was a First-Team All-Pac-12 Selection as a sophomore in 2017 and as a junior in 2018, and a Second-Team All-American as a sophomore (voted by the National Collegiate Baseball Writers Association).
2022
Made the Cubs Opening Day roster and was optioned to Triple-A Iowa four times throughout the season....Made 92 appearances (73 starts) at first base for the Cubs, committing just one error in 642 total chances across 646.1 innings at first...also made two appearances in left field and one in right field....For the big league club, batted .235 (59-for-251) in 101 games with five doubles, two triples, three home runs, 27 runs scored and 25 RBI....Collected a ML career-high three hits with one HR on April 23 vs. PIT in CHC's 21-0 route of PIT...his five RBI tied a career high, as he collected five RBI nearly two months later, this time at PIT on June 22....Hit safely in a season and career-high 8 consecutive games with the Cubs from July 26-Aug. 31....Went hitless in his final six games and 11 plate appearances from Sept. 29-Oct. 5....Had 87 SO vs. 29 BB...among all NL hitters who had at least 280 plate appearances, his 3.30 plate appearances per strikeout ratio was the 11th-fewest....57 of his 59 hits came vs. right-handed pitching (.257 AVG), as the lefty hit just .069 (2-for-29) vs. left-handers....With no runners on, he hit .215 (32-for-149)...with runners on, he hit .265 (27-for-102), including a .283 clip (17-for-60) with RISP....On first-pitch at-bats that got put in play, hit .619 (13-for-21)....In his 26 games for Iowa, he hit .298 (28-for-94) with six doubles, one triple, one home run and 10 RBI.
2021
In 2021, Alfonso made his major league debut with the Cubs ... was selected from Triple-A Iowa on Aug. 28 and played 18 games before he finished the season on the 10-day I.L. with a right middle finger tendon injury... Made his major league debut Aug. 29 at the White Sox, going 2-for-3 with a double ... recorded his first hit, a single, off Dylan Cease... Was 4-for-6 as a pinch-hitter and hit safely in 11 of his final 13 games, including a season-ending seven-game hitting streak (12-for-31/.387)... Hit his first career home run, Sept. 14 in Philadelphia off Kyle Gibson... Hit .284 (56-for-197) with 13 doubles, four homers and 32 RBI in 58 games for Iowa.
2020
Did not play due to the COVID-19 pandemic postponing the minor league season.
2019
Spent a majority of the season with Single-A Stockton, hitting .283 (122-for-431) with 60 runs, 24 doubles, three triples, eight homers, 55 RBI and 66 walks … posted a .383 OBP and was named a midseason California League All-Star...Played eight games with Triple-A Las Vegas at the end of the regular season, hitting safely in all eight contests … batted .406 (13-for-32) with two doubles, a triple, a homer and five RBI … had a 1.066 OPS.
2018
In his first pro season, Alfonso hit .285 (61-for-214) with 16 doubles, one triple, one home run and 28 RBI in 61 games for Single-A Vermont … stole seven bases.