Sean Burroughs -- the ninth-overall pick in the 1998 MLB Draft -- has suddenly passed away, it was announced on Friday. He was just 43 years old.

The former third baseman was coaching his son's Little League game in California on Thursday when he suffered cardiac arrest.

Burroughs was a standout for the Long Beach Little League World Series teams in 1992-93 ... becoming the first American-born pitcher to throw back-to-back no-hitters as he led his teammates to two titles.

His father -- former American League MVP Jeff Burroughs -- was the coach of the team.

Sean signed to play college ball at the University of Southern California, but chose to kickstart his professional career instead.

Before making his MLB debut, Burroughs played for the United States baseball team at the 2000 Olympics in Sydney, winning a gold medal.

Burroughs participated in seven MLB seasons -- suiting up for the San Diego Padres, Tampa Bay Devil Rays, Arizona Diamondbacks and Minnesota Twins.

He played in 528 games ... earning 463 hits, 143 RBI and 12 home runs in 1,664 plate appearances.

After leaving the majors, Burroughs continued to play independent ball and coach his son, Knox in the Long Beach Little League ... where his own career began.

LBLL president Doug Wittman and the org.'s board of directors released a statement on Friday ... saying, "It is with a heavy heart that I am writing this message to inform you that yesterday afternoon one of our Coaches, Sean Burroughs, tragically passed away."

"I have had the privilege of coaching with Sean for the past two years and he always came with a fun & friendly attitude the kids were drawn to, a wealth of baseball knowledge that could get any kid out of a batting rut and humility worth emulating."

"To say this is a huge loss is an understatement. But what makes LBLL special is our community, we are a family. Families celebrate the highest highs and lift each other up during the lowest lows."

The statement ended with a heartbreaking note ... "We will have his family in our thoughts and prayers during this time and try to end the season playing the kind of baseball Coach Sean would be proud of."