Danny Gardella was banned from major league baseball for playing in the Mexican League in 1946. He is remembered, and rightly so, for the legal battle that stemmed from his ban. Richard Goldstein's obituary of Gardella is in today's NY Times, and worth a place in your notebook.
Gardella's ban was part of a "group boycott" imposed by Commissioner Happy Chandler. The object of the boycott was to protect the reserve clause in a period where the potential for player movement among rival leagues was significant. Gardella sued Chandler and baseball over the boycott. The case was dismissed in 1947, based on the precedent that "baseball was not commerce," from the Supreme Court decision in the Federal League case of 1922. That case, the source of baseball's immunity from anti-trust law, stemmed from an earlier boycott of players who had signed with teams from the Federal League.
By that time however, the courts had recognized that the Federal League decision was shaky, and baseball risked having the precedent overturned if it took the case to the limit. Gardella's appeal of the dismissal was successful, and baseball ultimately settled the case rather than risk a full trial.
Gardella's contribution on the diamond of major league baseball was modest - he hit 18 home runs for the Giants in the war year of 1945, and failed to stick with a club after that. But his lawsuit was a significant guidepost for players in their struggle to eliminate the reserve clause. Like Goldstein, I'll give Danny Gardella the last word in this post:
"I feel I let the whole world know that the reserve clause was unfair," he said. "It had the odor of peonage, even slavery."