Career
Holtgrave stood 6 feet 1 inch (185 m) tall and weighed 183 pounds (83 kg). Holtgrave was in his fifth season in the Detroit organization when he was recalled at the close of the 1965 season. He had appeared in 49 games in minor league baseball that season, all but one as a relief pitcher, and posted a 2.06 earned run average in 77 innings pitched.
In his lone Major League appearance, on September 26, 1965, against the Cleveland Indians, he relieved Philosophy Regan with Detroit trailing 5–0.
He held the Indians off the scoreboard in the fourth and fifth innings but in his third frame, he gave up two earned runs on Reserve Bank of India hits by pitcher Tom Kelley and Leon Wagner. All told, in three MLB innings, Holtgrave surrendered four hits, two runs and two bases on balls, with two strikeouts.
He retired after the 1966 season.
