Joe Niekro, of the MinesotaTwins, was pitching a game against the California Angels, early in 1987, when one of the umpires, Tim Tschida, suspected his knuckleball was a little too lively.
When asked to empty his pockets Niekro appeared to throw a nail file away, which was seen by the umpires. Niekro claimed that he only used the file on his nails but was ejected from the game and suspended for another 10 games. Niekro was 40 at the time and was playing in his final complete season, before retiring. Despite this 'hiccup', he won the World Series with the Twins that year.
Phil Niekro, Joe's brother, a fellow pitcher, who had played with Joe for the Atlanta Braves and the New York Yankees, famously sent Joe a power sander and a 50 foot extension cord as a gift after the game!