It could be a historic day for the Baseball Hall of Fame.

The 2019 Class, which will be announced Tuesday at 6 p.m. ET, may not only have four or more candidates elected but could also feature the first candidate elected unanimously.

A candidate who receives 75 percent of the vote or more will be inducted into the Hall of Fame. Members of the Baseball Writers’ Association of America meeting certain requirements comprise the voting body, and the group has elected at least two candidates for the Hall of Fame for five consecutive years.

There are 20 newcomers on the ballot and 15 former players returning. Last year, the writers voted in Vladimir Guerrero, Trevor Hoffman, Chipper Jones and Jim Thome.

Here’s a look at some of the players who are likely to be elected and some who might miss the cut.

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According to Baseball Hall of Fame tracker, 53 percent of known ballots have been revealed and it appears writers are leaning toward electing four players into Cooperstown.

Closer Marino Rivera, righthanded starter Roy Halladay, designated hitter Edgar Martinez and righthanded starter Mike Mussina are among those who appear likely to get in. The tracker says Rivera is on all of the ballots listed and, if that remains the case Tuesday afternoon, it would be the first time anyone has ever been voted to the Hall of Fame unanimously.

Rivera, who won five World Series rings with the New York Yankees, is the all-time leader in saves with 652 and is widely considered to be the greatest closer of all-time.

Halladay pitched for the Toronto Blue Jays and Philadelphia Phillies, won two Cy Young awards and is the only National League pitcher ever to throw a no-hitter in the postseason, and just the second pitcher ever. He recorded 2,117 strikeouts during his 16-year career. He died in a plane crash in November 2017.

Martinez hit .312, had a .933 OPS and 309 home runs in an 18-year career with the Seattle Mariners. Writers have been slow to vote him into the Hall of Fame because he was a designated hitter for the majority of his career. He received 70.4 percent of the vote last year and his candidacy has gained momentum with each passing year.

Mussina, who pitched for the Baltimore Orioles and New York Yankees, may just miss out or just eek over the line on Tuesday. Some writers will point to his only winning more than 20 games once in his 18-year career, never winning a Cy Young award and not winning a World Series. His supporters point to his 3.68 ERA during an entire career spent in the vicious American League East and a sterling 270-153 record, good for a .638 winning percentage. He received 63.5 percent of the vote last year.

ON THE FRINGE

Barry Bonds, Roger Clemens and Curt Schilling are among the former players who may gain votes to get within striking distance of Cooperstown, though they're unlikely to make it this year.

Clemens received 57.3 percent, Bonds received 56.4 percent and Schilling received 51.2 percent of the voting last year. It will be Clemens and Bonds’ seventh year on the ballot and Schilling’s sixth year.

Bonds and Clemens have taken flack from some writers for their links to performance-enhancing drugs.

Bonds is the all-time home run leader with 762 and astonishingly recorded 2,558 walks. He won seven MVP awards over his 22-year career with the Pittsburgh Pirates and San Francisco Giants. He’s also the single-season home run leader with 73 in 2001.

Clemens won 354 games, recorded a 3.12 ERA and had 4,672 strikeouts with the Boston Red Sox, Toronto Blue Jays, New York Yankees and Houston Astros. He also has two World Series rings, an MVP award and seven Cy Young awards in his trophy case.

Schilling, who was also among the most dominant pitchers of his era, particularly in the postseason, may not get in for controversies off the field. Schilling was suspended and fired from ESPN after his political comments sparked an uproar. But he struck out 3,116 batters and helped win three World Series -- including a key role on the 2004 Boston Red Sox squad that broke an 86 year drought -- in his career.

He also recently received President Trump’s endorsement for the Hall of Fame as well.

NOT COMING BACK?

Due to a stacked ballot, there are several former standout baseball players who may not get back on the ballot if they don’t make the 5 percent threshold, including a handful of first-timers.

Michael Young, Lance Berkman, Roy Oswalt, Miguel Tejada, Rick Ankiel, Jason Bay, Freddy Garcia, Jon Garland, Travis Hafner, Ted Lilly, Derek Lowe, Darren Oliver, Juan Pierre, Placido Polanco, Vernon Wells and Kevin Youkilis are among those who are in serious danger of not returning for the 2020 ballot.

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Andruw Jones, who hit 434 home runs, had a .823 OPS and won 10 Gold Gloves in centerfield, is in danger of not returning. Andy Pettitte, who recorded a 3.85 ERA and won five World Series rings with dominant postseason outings, is in the same boat as Jones.

These players may have to wait for consideration by the Veteran's Committee, which evaluates different eras of players each year.