Oakland Athletics legend Dave Henderson has died at age 57, reports Bob Nightengale of USA TODAY:

Dave Henderson, the gregarious man known as Hendu, died Sunday, one month after getting a kidney transplant. He will be tremendously missed. — Bob Nightengale (@BNightengale) December 27, 2015

Nightengale says his cause of death was cardiac arrest:

Dave Henderson, who had a kidney disease and had recent kidney transplant, sadly died of cardiac arrest. Great, great man — Bob Nightengale (@BNightengale) December 27, 2015

Nicknamed "Hendu", Henderson was a major part of four American League pennant teams in his career and was a key player in the 1989 World Series win for Oakland. He played for the Mariners, Red Sox, Giants, A's, and Royals from 1981-1994.

In 1987, Henderson saved the Boston Red Sox from elimination in the 1986 ALCS with his ninth inning Game 5 home run against the California Angels, and hit the go-ahead 11th inning sacrifice fly. He went on to hit two home runs and hit .400 in the Boston Red Sox's incredible 1986 World Series loss against the New York Mets.

Hendu joined the A's in 1988 and played six seasons in Oakland, with four of those teams advancing to the postseason. For Oakland's 1988-1990 teams, Henderson was 25-for-87 and hit four home runs and nine doubles. Injuries prevented him from playing for Oakland in the 1992 ALCS.

After a distinguished playing career that included a trip to the 1991 All-Star Game, he returned to his original team, the Seattle Mariners, and was most recently a part of the Mariners radio broadcasting team.

The A's released a statement, "The A’s are saddened to hear of the passing of Dave Henderson. Henderson was an instrumental part of the A’s 1989 World Series Championship club and an even more impactful member of the A’s family and community. Hendu and his smile will be sorely missed. Our thoughts are with his family."

★ ★ ★

I'm too young to remember much of Dave Henderson's exploits on the field, but every time I hear someone who knew Hendu talk about him, you hear things like this:

One thing always rang true with Hendu. He loved playing the game. Brought joy and style to the ballpark every single day. — Carl Steward (@stewardsfolly) December 27, 2015

Rest in peace, Dave Henderson. Met him at an #Athletics FanFest when I was a kid, was a really nice guy. Sad news. — Adrian Garro (@adriangarro) December 27, 2015

Terry Steinbach says Dave Henderson would "instantly pick you up, put you in the right frame of mind." https://t.co/OWrqvPONSy — Susan Slusser (@susanslusser) December 27, 2015

Bill King always called him the "Gap-Toothed Center Fielder," writes Ken Korach in Holy Toledo, "We just had that funny relationship of razzing each other a little bit. Some friendly humor when we'd meet before games or after games," Henderson said.

I was lucky enough to see Henderson at 2014 A's FanFest, and all I can remember is how everything he said reminiscing about the 1989 World Series was imbued with this sense of joy, and how fortunate he was to have made baseball his career. He threw out the first pitch at Game 1 of the 2013 ALDS in Oakland, and you can just see how much he loves talking about the game and being in the game, speaking to MLB.com just beforehand:

Rest in peace, Hendu. You are missed.