Though he was never called a Cardinal he played for this team from 1884-1887, 1892.
While Shohei is seen as a 21st century Babe Ruth, Babe Ruth was a 20th century Bob Caruthers. Granted his numbers aren't staggering by today's standards but for the late 1800s he was a monster from both sides.
In a 9 year career managed 900 strikeouts, career ERA of 2.83, W-L 218-99, .282 batting average, 29 home runs, and 359 rbi.
He helped our Brown Stockings win 3 consecutive American Association titles and 1 World Series title over what would become the Cubs. The only World Series every claimed by a team from neither the national or American League.
Obviously he never wore a number but the way to retire is clear. In the outfield mural have his mural be the shade of brown this team once wore.