CHICAGO -- The Baseball Hall of Fame is full of all-time great Cubs. When Lee Smith gained entry most recently, he joined an impressive class that includes the likes of Ernie Banks, Billy Williams, Ron Santo, Ryne Sandberg and Fergie Jenkins.

The list goes on, but could it have been even longer by now?

MLB.com is taking a club-by-club look at the best players who are currently not in the Hall of Fame. For this exercise, we focused only on retired players who are eligible but have not yet been voted in, or were eligible and did not stay on the ballot.

Here are five of the best players in Cubs history who do not have a plaque in the hallowed halls in Cooperstown:

1. Sammy Sosa, 1992-2004 with Cubs
Key fact: Only player in MLB history to hit 60-plus homers in three seasons.

Sosa's numbers are undeniably Cooperstown worthy. It seems that the main reason behind the all-time slugger's struggle to gain entry into the Hall of Fame (he fell off the BBWAA ballot in 2022 after 10 years of eligibility) has been lingering suspicions over how he went about compiling his powerful home run feats.

Still, Sosa is the Cubs' home run king with 545 of his 609 career blasts coming with the North Siders. In 1998, Slammin' Sammy captivated the nation, alongside Mark McGwire, in the pursuit of Roger Maris' previous single-season record of 61 home runs. Sosa ended with 66 (second to McGwire's 70) and won the National League MVP.

From 1998-2001, Sosa averaged 61 homers and 149 RBIs with a .310 average and 1.058 OPS. With the Cubs, Sosa made seven All-Star teams, won six Silver Slugger Awards and amassed 1,414 RBIs (third in team history), 873 extra-base hits (third), 3,980 total bases (fourth), 1,245 runs (sixth) and 58.8 WAR (sixth).

His .569 slugging percentage and .928 OPS with the Cubs each rank second in franchise history, while Sosa's rate of one homer per 12.8 at-bats ranks first in team history.

2. Stan Hack, 1932-47 with Cubs
Key fact: 54.8 WAR ranks second among Cubs players not in the Hall of Fame.

In a 1996 book called "Wrigleyville," former Cubs great Phil Cavarretta said of his teammate Hack: "Stan never got the credit he deserved. ... To me, with his stats and knowing Stan Hack, I can't understand why he isn't in the Hall of Fame."

Cavarretta may have a point, given that Hack was one of the best third basemen of his era.

Over 1,938 games with the Cubs, Hack hit .301/.394/.397 and had 1,092 walks compared to just 466 strikeouts. His 2,193 hits are the sixth-most in franchise history. Hack was at third base on Opening Day for the Cubs in 12 of his 16 seasons and he appeared in four World Series, hitting .348 with an .857 OPS in 18 Fall Classic games.

3. Mark Grace, 1988-2000 with Cubs
Key fact: His 456 doubles trail only Cap Anson (529) in Cubs history.

With the exception of Pete Rose, each hitter who led a decade in hits from 1900-1989 is in the Hall of Fame. That group includes: Honus Wagner, Ty Cobb, Rogers Hornsby, Paul Waner, Lou Boudreau, Richie Ashburn, Roberto Clemente and Robin Yount. The MLB hit leaders of the 2000s (Ichiro Suzuki) and 2010s (Robinson Canó) also would appear poised for entry into the Hall.

Grace led all MLB hitters in both hits (1,754) and doubles (364) in the 1990s, but was knocked off the Hall of Fame ballot after receiving just 4.1 percent of the vote in 2009.

Grace won four Gold Gloves at first base, made three All-Star teams and finished his 16-year career with a .303 average. He collected 2,201 of his 2,445 career hits with the Cubs and ended his career with 1,075 walks versus 642 strikeouts. Grace reached the playoffs twice with the Cubs and famously hit .647 (11-for-17) in the '89 NL Championship Series against the Giants.

4. Charlie Root, 1926-41 with Cubs
Key fact: Pitched in four World Series.

Root is the Cubs' all-time leader in innings (3,137 1/3), games (605) and wins (201). Since 1920, only Rick Reuschel (48.3) has more WAR than Root (37.8) in a Cubs uniform among the players not enshrined in the Hall of Fame. Root is also one of 11 pitchers in baseball history to have at least 300 starts and 150 games finished in a career.

Root is famous for being the pitcher on the mound when Babe Ruth is believed to have called his shot in the 1932 World Series. But the Cubs pitcher also helped lead the team to pennants in '29, '35 and '38. While with Chicago, Root had a 3.55 ERA with 177 complete games, 171 games finished, 42 saves and 21 shutouts.

5. Phil Cavarretta, 1934-53 with Cubs
Key fact: Won the 1945 NL Most Valuable Player Award.

There are a few players that could have been mentioned to round out this list.

Hippo Vaughn had a sparkling 2.49 ERA in his career from 1908-21. Bill Buckner spent parts of eight seasons with the Cubs in a 22-year career that included 498 doubles and 2,715 hits. Ed Reulbach had a brilliant ERA (2.28) in his career, helped the Cubs to World Series triumphs in 1907-08 and scores a 101 on Bill James' Hall of Fame Monitor (with 100 being a likely Hall of Famer). Bill Nicholson logged 38.1 WAR while with the Cubs.

We'll conclude with Cavarretta, whose name can be found throughout the Cubs' all-time Top 10 lists. He ranks fifth in team history in triples (99), seventh in walks (794) and 10th in runs (968), hits (1,927) and RBIs (896). He played in three World Series ('35, '38 and '45), picked up an MVP and batting title in '45 and made the All-Star team four times.