Whether Boston's Jim Rice follows Henderson in is the big question. Red Sox great Carl Yastrzemski was the last left fielder elected to the Hall in 1989.
Jeff Idelson, the president of the Hall, will make the announcement via MLB.com and the MLB Network during a Hall of Fame Election Special at 1:30 p.m. ET on Monday with a prime-time special later that night at 9 p.m. ET, celebrating the careers of those players who made it.
Former Yankees and Indians second baseman Joe Gordon was elected by a Veterans Committee this past December and will be inducted along with anyone selected from the writers' ballot on July 26 in Cooperstown, N.Y.
Rich "Goose" Gossage was the only player elected by the BBWAA last year. And Tony Gwynn and Cal Ripken Jr. were the last first-time electees in 2007. Ripken earned 98.5 percent of the vote (537 of 545 ballots cast) and Gwynn had 97.6 percent (532 votes).
A candidate needs 75 percent of the ballots cast for election.
Henderson is among 10 newcomers on the 23-man Hall of Fame ballot, the smallest in history, which was mailed to the writers in early December. Those ballots had to be returned with a postmark dated no later than Dec. 31.
Rice, the former Red Sox left fielder and one of 13 holdovers from the 2008 ballot, is on it for the 15th and final time, giving the writers one last opportunity to pick him. So was left-hander Tommy John. Players may remain on the ballot for up to 15 years provided they receive at least 5 percent of the vote each year.
Rice clearly has the best chance of going in with Henderson. He missed the cut last year by merely 16 votes.
While Rice earned 392 votes among the 543 ballots cast for 72.2 percent, John's percentage was only 29.1 (158 votes). In 14 tries, the 288-game winner has never finished higher than 30 percent, with 29.6 percent in 2006 his best finish.
Rice's percentage last year was the highest for any player not elected and no player who has reached the 70-percent plateau has failed to be elected the following year.
A .298 career hitter with 382 home runs, 2,452 hits and 1,451 RBIs in 16 seasons, all with the Red Sox, Rice had four seasons of more than 200 hits, led the American League in home runs three times, RBIs twice, once in hits, twice in slugging percentage, was the AL Most Valuable Player in 1978 and was an eight-time All-Star.
"I wouldn't say it's well overdue," former catcher Bob Montgomery, a close friend and one-time Boston teammate of Rice from 1974-79, recently told the Providence Journal. "But I would say overdue. The one thing that sticks out in a lot of voters' minds is the fact that he doesn't have 400 home runs. I really believe if he had the 400 homers he would have been in there four or five years ago. That's just a guess on my part, but he definitely deserves it."
Rice's numbers, though, don't compare favorably with Yaz, another one of his Boston teammates from 1974-83.
Yastrzemski batted just .285, but he had 3,419 hits, 452 homers and 1,844 RBIs, won the AL's Triple Crown and was the league's MVP in 1967 and was an 18-time All-Star in 23 seasons. He led the league three times in batting, two times in total hits, once each in homers and RBIs, three times in doubles and runs scored, five times in on-base percentage and three times in slugging percentage.
Other more distant possibilities for selection this year were Andre Dawson, a former National League Rookie of the Year (1977) and MVP (1987), who was on the ballot for the eighth time, and Burt Blyleven, fifth on the all-time list with 3,702 strikeouts, who was on the ballot for the 12th time.
Dawson started to close in last year with 358 votes (65.9 percent) and Blyleven was right behind him with 336 votes (61.9 percent).
Henderson is the all-time leader in runs scored (2,295) and stolen bases (1,406). He established himself as baseball's supreme leadoff hitter by banging out 3,055 hits in a 25-season career spanning four decades (1979-2003) that included four tours with the Athletics and stops with the Yankees, Blue Jays, Padres, Angels, Mets, Mariners, Red Sox and Dodgers.
A career .279 hitter with a .401 on-base average and 297 home runs, Henderson won World Series rings with the 1989 A's and '93 Jays, was the AL MVP in 1990 and set the bar so high with the single-season stolen base record of 130 in 1982 that no player since then has come within 20 bags of equaling it. His 81 home runs leading off games are the most in Major League history.
On top of all that, La Russa said: "His teammates really enjoyed him. He wasn't one of those guys who was arrogant and separated himself once he walked into the clubhouse. He'd play dominoes and he'd mess around. He was well-liked, which I don't think is well-known publicly.
"He was always a dynamic figure. His grammar sometimes got him in trouble, but that was Rickey."
What also got Henderson in trouble were the times he became withdrawn and sullen about his contract, particularly when the deal he was fulfilling began to fall behind the market value of others who signed after him.
And there might be some validity to those brooding periods. Henderson came up with the A's in 1979 at the end of the reign of the penurious Oakland owner Charlie Finley. Even though that was the first blush of free agency, Finley put together a youthful outfield of Henderson, Dwayne Murphy and Tony Armas Sr. and the infamous Charlie O. enjoyed chortling about paying that trio about $100,000 a year as a combo.
Henderson earned about $50 million during his career, hardly a shallow figure, but a paltry sum in comparison to the eight-year, $180 million deal Mark Teixeira recently signed with the Yankees. And thus far Teixeira hasn't matched any of Henderson's records or accomplishments.
No wonder there were times when Henderson was bitter.
"There's a certain perception of him being a troublemaker," La Russa said. "And there were times when Rickey took care of himself. There were times when what was good for Rickey wasn't what the manager or management thought was good for the team. He and I had a couple of issues about that. And that got a lot of publicity.
"But the point is, he's probably one of the best teammates among superstars that you're ever going to find."