I'll admit, a player's uniform number is a minor thing in terms of his career and his contributions to the team. Nevertheless, many players are quite attached to their numbers, and as someone who literally co-wrote the book on Cubs uniform numbers, it's something important to me, and perhaps at least interesting to you. So let's have a look.
Miguel Montero has worn No. 26 throughout his nine-year career with the Diamondbacks, as shown on his baseball-reference page. 26, of course, is retired for Hall of Famer Billy Williams, who wore it through most of his Cubs career, although, as you can see at that link, he wore No. 4 and No. 41 in his two September callups before he became a regular in 1961, and wore two different numbers with the Athletics.
Jon Lester has worn No. 31 through most of his career with the Red Sox and A's, although his baseball-reference page shows him as wearing No. 62 for part of his first season in Boston in 2006. No. 31 is retired for the Cubs for Greg Maddux and Fergie Jenkins. I know some of you don't think No. 31 should be retired, and note that both Maddux and Jenkins wore different numbers at some stages of their careers. Both, though, had their biggest fame wearing No. 31, and it should be noted that Maddux could not get No. 31 with the Padres, because San Diego has it retired for Dave Winfield.
One thing that I think should not be done in either case is "unretiring" either number. The point of retiring a number is to honor it forever. When Omar Vizquel asked Luis Aparicio if the White Sox would "unretire" his No. 11 (since Vizquel's usual No. 13 was taken by manager Ozzie Guillen), he should have politely been told "no." It was said that this was to "honor" Aparicio, but the honor had been given to the retired Hall of Famer. Once a number is retired, in my view it ought to stay retired.
So what numbers will these players take? Lester could go back to No. 62; in all of Cubs history just five men have worn that number:
Walt Dixon (coach, 1964-65), Felix Sanchez (2003), Bob Howry (2006-08, 2010), Marcos Mateo(2010-11), Henry Rodriguez (2013)
Not exactly a Hall of Fame list there -- Lester could make it his own. Or, he could take another number with a "1" in it -- maybe 11? The last Cubs pitcher to wear No. 11 was Bob Muncrief, in 1949. Muncrief actually pitched in two World Series, in 1944 for the St. Louis Browns and in 1948 for the Indians. I kind of like that idea. Or how about No. 1? It's currently taken by third-base coach Gary Jones, but if Lester wanted it, I'm sure he could afford to give Jones the traditional gift to get it. No Cubs pitcher has worn a single-digit number since 1948, when Tony Jacobs took the mound for one game wearing No. 2.
If Lester doesn't take No. 62, Montero could reverse his digits à la Carlton Fisk and take that uniform number, or take over John Baker's No. 12, or go single-digits and wear No. 3, which has never before been worn by a Cubs catcher (all the others on that list are players from other positions or coaches).
As I said, not hugely important, but interesting, and it will have to be solved soon as they usually hold up a jersey with the new player's name at the news conference, or even have him try it on for size. Jason Hammel can have his No. 39 back (though numbers don't seem to mean much to him as he's worn four different ones in his career), since no one else wore it after the July trade that sent him to Oakland.
I can put only one poll here so I'm making it about Lester; you can leave your thoughts on Montero in the comments.