Quite a few players (mostly outfield) have worn 23 while on the Mets. Here's the list and years they wore it:
Outfielders- Joe Christopher (62-65), Billy Murphy (66), Leroy Stanton (70-71), Jesus Alou (75), Leon Brown (76), Bernard Gilkey (96-98*), Jermaine Allensworth (98*), Matt Lawton (01^), McKay Christensen (02**), Esix Snead (02**), Marlon Anderson (07^^), Chris Carter (10), Mike Baxter (11*^)
Infielders- Bob Heise (68-69), Ted Martinez (74), Doug Flynn (77-81), Brian Giles (82-83), Chris Donnels (91-92), Tim Bogar (93-95), Jason Phillips (03-04), Julio Franco (06-07^^)
Catcher Brian Schneider (08-09)
Pitchers- Pat Mahomes (99-00), Brain Rose (01^), Kazuhisa Ishii (05), Blaine Boyer (11*^)
Coaches Bud Harrelson (85-88)
*In 1998 Gilkey wore 23 until July and it was handed over to Allensworth in August
^In 2001 Rose wore 23 for 21 days in April and gave it over to Lawton in July
**In 2002 Christensen had 23 for a week in April and Snead had it for 27 days in September
^^In 2007 Franco had 23 until July when he handed it off to Anderson
*^In 2011 Boyer wore 23 for 9 days in April, Baxter took it in August
Manny Trillo, one of my favorite Cubs, wore it both times he played for them.
Lou Brock wore uniform number 24 with the Chicago Cubs from 1961-1964, and number 20 with the St Louis Cardinals from 1964 - 1979.
Maddux wore No. 31 for the Chicago Cubs from 1986 to 1992, and again in 2006. He also wore 31 as a member of the Atlanta Braves from 1993 to 2003. Maddux wore No. 36 for the Los Angeles Dodgers in 2006 and 2008, and No. 30 for the San Diego Padres in 2007 and 2008.
In MLB ... 1) Pitcher Bill Lee wore #11 for the Chicago Cubs from 1937-1942. 2) Infielder Lee Bales wore #11 for the Atlanta Braves in 1966. 3) Pitcher Lee Howard wore #11 for the Pittsburgh Pirates in 1946. 4) Outfielder Lee Mazzilli wore #11 for the Pittsburgh Pirates in 1983 and 1984. 5) First baseman/outfielder Lee Stephens wore #11 for the Texas Rangers from 1996-1998.
Berra wore #8.
Manny Trillo, one of my favorite Cubs, wore it both times he played for them.
Mark Grace wore the numbers 28, and 17 during his rookie season with the Chicago Cubs in 1988, and wore the number 17 the rest of his career.
No player has ever worn number 70 for Chicago.
George Lucas was the only one.
Young, an outfielder who played two seasons for the Chicago Cubs, wore No. 23 in 1965 and No. 29 in 1969.
Jeff wore the number 20 in homage to his father who also wore that number for the '63 Yankees. Once he was traded to the Chicago Cubs, he was reassigned the number 11
Miller played with the Cubs in the 2003 season. He wore #27.
lee smith pitcher for the Chicago cubs
Rafael Palmeiro wore number 25 while with the Cubs.
Lou Brock wore uniform number 24 with the Chicago Cubs from 1961-1964, and number 20 with the St Louis Cardinals from 1964 - 1979.
billy Williams Hall of famer from the Chicago Cubs
In 2010, wide receiver Johnny Knox wore #13 for the Chicago Bears.