[4] In 1900, he joined the Detroit Tigers, then a minor league club, compiling a 6-5 record with a 3.97 earned run average (ERA).

[3] He was described by a writer in the Detroit Free Press as having "a great pitching arm and a physique as strong as a young lion.

In the Tigers' inaugural season as a major league club, Siever and Roscoe Miller were the team's leading pitchers.

[1] In 1902, Siever led the American League with a 1.91 ERA, and his Adjusted ERA+ of 195 remains the second best in Tigers history for a pitcher with more than 150 innings pitched.

[1] On August 11, 1902, Siever and Rube Waddell engaged in a pitching duel that held both sides scoreless through 12 innings.

[1] The following year, Siever compiled an 18-11 for the 1907 Tigers team that went 92-58 and lost to the Chicago Cubs in the 1907 World Series.

[1] Siever started one game in the 1907 World Series and gave up two earned runs in four innings pitched.

[1] The Detroit Free Press later called 1907 season "the zenith of his career" and described a change in strategy in Siever's approach to the game: "While control and speed were 'Eddie's' best assets in his early career, in later years he resorted to the use of a slow ball, by using it in conjunction with a ball that burned its way plateward, he got away with many sensational victories.