"Stan and the Blues" by Ed Levitt
Oakland Tribune | 1969-05-04 p. 47
"With all that, he finds time for a hobby -- magic. He is a fiend on card tricks.
His favorite card trick is to blindfold himself, have someone pick a card out of a deck over a table, cover the cards with a newspaper, then take a knife and, still blindfolded, stab the card that had originally been picked."
While looking for this I also found references to other baseball players doing magic:
Washington Senators Thursday sought a way out of seventh place by hiring a magician for their manager. Joe Kuhel, who does card tricks and is a member of the Society of American Magicians, signed a one year contract to manage the American league team.
_Lethbridge (Alberta, Canada) Herald_ Oct 10, 1947 p. 15
"Joe Abreu, rookie Cincinnati infielder, is quite a magician. He can do all sorts of card tricks, pull rabbits out of hats, etc."
_Sporting News_ April 2, 1942 p. 6
"He [Joe Kuhel] picked up his first knowledge of magic from Carl Zamloch, the former Cub Pitcher , who is now a big shot with the Signal Oil Co., on the Coast. Zamloch learned his magic from his father, one of the greats of the art of mystifying audiences when grandpa was a boy. " _Sporting News_ April 30, 1942 p. 2
"Mort [Cooper 1938 - 1949, mostly StL Nat and Bos Nat] is a push-over for glasses that leak when you drink out of them, sneezing powder, locks that unlock only when turned upside down behind your back, card tricks, and little flowers that fit in your lapel and squirt water all over the over-curious." _Sporting News_ October 1, 1942 p. 12
"[Paul] Waner proved an entertaining story-teller and amateur magician in the grille room after dinner, telling some fishing whoppers and pulling some downright clever parlor and card tricks." _The Charleroi [Pennsylvania] Mail_ 1951-06-26 p. 5
"Scotty had card sense, preferred hearts and bridge, entertaind with card tricks. He excelled at solving mathematical problems." [Everett Scott 1914 - 1926, mostly NY and Boston] North Carolina | Burlington | Daily Times-News, The | 1943-06-21 p. 7
"Carl Zamloch, former pitcher, and a son of the famed magician, Herman the Great, [I believe Carl's father was Anton Zamloch; he had a son, also named Carl Zamloch, who was active in the PCAM] afforded delegates to the convention occasional entertainment with his card tricks and sleight-of-hand stuff. " _Sporting News_ December 11, 1946 p. 28
"When Musial says he does "a little magic," he is not poking fun at pitchers. He doesn't mean with the bat, but with card tricks and such. . . . "When we trained at Cairo, Ill., while wartime travel limits were on, Clyde [sic] Keefe taught Dickson [Murray Dickson 1939 - 1958, mostly StL and Pit], Donnelly [Sylvester Urban "Blix" Donnelly, 1944 - 1951, St.L and Phi.] and me lots of tricks. Keefe was a life insurance manager there, and had studied magic, and could make publick appearances. I am not that good, but I know a number of tricks which the real magicians do." " _Sporting News_ August 2, 1950 p. 4
"Stan Musial, most famous of all present day baseball players, was recently featured in a Saturday Evening Post write-up and his keen interest in magic was described, illustrated with a large photo of Stan doing card tricks for the family, the card-to-be-found sticking prominently out of a hip pocket. While many of the St. Louis Cardinals axe magical enthusiasts, Stan has the largest collection of props and does the most tricks." _The New Phoenix_ # 315, p. 61
"Tony Returns from Army With Hatful of Card Tricks"
"To baseball fans, the Yankee shortstop is Tony Kubek. To his teammates, he is Anthony the Great, Baseball's Most Amazing Sleight of Hand Wizard.
When Kubek returned from his Army hitch, he came back to the Yankees with a well-grounded knowledge of the duties and tribulations of a rifleman in an infantry platoon. He also picked up a few card tricks, the now-you-see-it-now-you-don't kind that have all his mates trying to emulate the wizardry of Anthony the Great." _Sporting News_ September 1, 1962 p. 8
"On the long "red eye" plane ride back to New York, Sam [McDowell, 1961 - 1975, pitched for Cleveland] showed [Ralph] Houk his repertoire of card tricks, of which he has many." _Sporting News_ July 7, 1973 p. 13
"Moose [Haas 1976 - 1987, pitched for Milwaukee] considers himself a novice magician, but he is confident enough in some of his sleight-of-hand to show a few tricks to teammates." _Sporting News_ November 10, 1979 p. 47
Other athletes mentioned to do magic:
Jerry Lucas (NBA)
Lindsey Hopkins (Indy 500 -- Pete Biro, do you know him?)
Chuck Fusina (NFL/USFL)
Buzzie Bavasi (Brooklyn and LA Dodgers front office)
Lew Tendler (boxer)
Fred "Newt" Hunter (baseball coach/scout 1930's)
Lou Holtz (college football coach)
Chuck Ramsey (NY Jets punter)