"When I was first going bad, I listened to every single person that would tell me anything. If my grandmother had told me to go up lefty, I would have gone up lefty. When you’re hitting .180—not (even) .190, I mean, I couldn't listen to myself about it. So I tried everything. It was really weird. It was really two years of experimentation, pretty much. I thought if I moved everything around weird, that something would click. Nothing ever really clicked." - Matt Antonelli in The San Diego Union-Tribune (Tim Sullivan, It’s clicking for Padres’ Antonelli, 03/18/2010)

Antonelli was the Massachusetts Player of the Year in football, was selected to the all-state team in hockey, and was a runner-up for baseball in his senior year at St. John's Prep. He was drafted as a third baseman by the San Diego Padres with the 17th pick of the 2006 Major League Baseball Draft. In July 2007, Antonelli was named the best second base prospect in the minors by Kevin Goldstein of Baseball Prospectus. In November 2007, Matt was ranked as the #1 second base prospect and #27 prospect overall in baseball, on a list polling 20 members of the scouting community and compiled by Jonathan Mayo of minorleaguebaseball.com He won the Texas League Championship with the Missions in 2007.

In 2008, Antonelli played for the Padres' AAA farm club, the Portland Beavers. He struggled at the plate most of the year, hitting just .215, but kept his good eye and ended up with 76 walks. In August he found some success, hitting .290 for the month, with 4 home runs and a .393 OBP. Antonelli was called up to the Padres on September 1, 2008, where he promptly laced a single off Greg Maddux of the Dodgers for his first hit in the major leagues. He then went hitless in his next 20 at bats, but then got 7 hits in his next 13 at-bats with 3 walks, including his first home run, on September 15, off of Colorado Rockies pitcher Jason Hirsh.

During the 2010 Spring Training period he suffered a Hamate bone injury and then a broken wrist, requiring multiple surgeries. While the club kept him on the official roster he was unable to play, and was granted free agency at the end of the 2010 season. The hand injuries became a chronic issue throughout the rest of his career. He tried to catch on with the Nationals, Orioles, Yankees, and Indians to return to MLB, without success.

After retiring, Antonelli received several calls from independent league teams. However, he declined all of those offers due to his injury history and his belief he could not make it back to the Major Leagues, and decided to focus on a potential career of coaching.

Antonelli is well known for his YouTube channel, Antonelli Baseball, for which he makes baseball-related videos. Recently, Antonelli has started a Road To The Show series on his channel which gained popularity and slowly spiked his subscriber count. Says Matt on The Score: "Now I've done, I think, almost 80 different videos showing my Road to The Show character, and I’ve gotten a lot more subscribers because of that. I think it just brings a different dynamic to the channel. It brings a new audience" The channel has more than 174,000 subscribers and over 39,323,000 views as of May 2021. He also was an assistant baseball coach at the College of the Holy Cross and Wake Forest University.

Matt is on Twitter @MattAntonelli9

(excerpted from Baseball Almanac, BR Bullpen & Wikipedia)