In September 1903, the St. Louis Cardinals draft Shannon from St. Paul as part of that years Rule 5 draft. In his first season in the big leagues, he played in 134 games and stole 34 bases. He batted .280 in his rookie season. His batting average fell over the course of the next two seasons, though he remained a threat to steal on the base paths. On July 13, 1906, the Cardinals traded him to the Giants for catcher/outfielder Doc Marshall and OF/INF Sam Mertes. Despite having a .265 batting average in 1907, Shannon led the National League in runs scored with 104. He also led the league in at bats and plate appearances as well. 1908 would be his final season as a major league player. He struggled to start the season, and placed on waivers by the Giants. The Pittsburgh Pirates claimed him off waivers and paid the Giants $1,500 for his rights. However, he continued to slump and on September 30, 1908, he played his final game, going one for four against the St. Louis Cardinals, ironically, the very team he'd made his major league debut for a few seasons earlier.[2]
Hoping to catch the eyes of scouts and make his way back to the big leagues, Shannon signed with the Kansas City Blues of the American Association. During a three-year stint his batting slump continued where in 1911, while appearing in 52 games, the best he could muster was a .216 batting average and he retired after the season. Shannon still made another comeback at the age of 38 a couple years later, this time for the Virginia Ore Diggers of the Northern League. Playing in 63 games, Shannon batted .236 and retired after the 1913 season.[3]
After his playing days were over, Shannon returned to baseball again, this time as an umpire in the Federal League, a league that would go on to sue both the American and National Leagues, accusing them of having a monopoly on major league baseball. The Federal League was hoping to become a third major, but the lawsuit drained the league of revenue and it went out of business.
Death
Spike Shannon died on May 17, 1940, at the age of 65.[4]