Due to Tiger pitching injuries, and with many top players still in the military late in World War II (Houtteman was too young for the draft), he made his major league debut on April 29.
At 17 years old, he was the youngest player in the American League in the 1945 season before being optioned back to Buffalo, where on June 20 he threw seven no-hit innings, facing only 22 batters in the process, but lost the game 2–0 in extra innings.
He also appeared in 13 games as a relief pitcher, and finished his minor league season with no wins, two losses and an ERA of 5.33 in just over 25 innings pitched.

Houtteman was the youngest major leaguer in 1946 but played only one game for the Tigers that season, allowing eight runs and fifteen hits in eight innings.
He spent most of 1946 in the minor leagues, finished at 16–13 and led the league in strikeouts.
At the end of the season, Houtteman was named by six of the eight International League managers as the top pitching prospect in the league, leading the league in strikeouts with 150, pitching over 200 innings, finishing second in victories with 16, and amassing an 11–2 road record.
Minor league third baseman Johnny Bero liked Houtteman's fielding ability so much that he called him "a fifth infielder."

Despite his newfound top prospect status Houtteman remained in Buffalo at the beginning of the 1947 season before being recalled to the Tigers in July.
He was relegated to the bullpen for a time, and saw little action.
But after Hal Newhouser, Fred Hutchinson and Dizzy Trout were used in two days, Tiger manager Steve O'Neill decided to start Houtteman against the Washington Senators for only the second start of his career.
He tossed a five-hit shutout and Tiger general manager Billy Evans said, "In 40 years I've never seen a better pitching job by a first-year pitcher.
We now know that Houtteman is really a big leaguer".
He followed this with another five-hit victory against the Boston Red Sox, then pitched a three-hit shutout in September against the St. Louis Browns.
He finished the season at 7–2 with a 3.42 ERA, seven complete games and two shutouts.
His performance in 1947 caught the attention of New York Yankees star and future Hall of Famer Joe DiMaggio, who said of Houtteman and Bob Lemon, "They have more stuff and more pitching sense than any other young fellows I've seen come up in a long while".

The 1948 Detroit Tigers season began with Houtteman in the starting rotation.
Things started off poorly, however, as Houtteman lost his first eight decisions.
Two of the first five losses, though, were by one run, and he had little run support.
The 0–8 start and lack of run support led to his being called "Hard Luck Houtteman" in the media.
His first victory that year came against the Senators, in which he also drove in the winning run.
After winning his next start, he defeated the Philadelphia Athletics allowing only five hits, and avoided another loss.
But he then lost eight more games and finished the season at 2–16.
His teammates and the media attributed this to bad luck rather than bad pitching, and still regarded him as a prime prospect.
Newhouser said, "The kid has had nothing but bad luck since the season opened", while Fred Hutchinson said, "He shouldn't have lost more than three or four games had he gotten an even break".
But his 4.66 ERA was only 0.06 higher than the major league average.

As 1949 spring training began, Houtteman was nearly killed.
In Lakeland, Florida on March 10, while driving home from Florida Southern College, he crashed into a fruit truck fracturing his skull.
Originally listed in critical condition (a priest stood by to administer the last rites in extremis), he recovered rapidly and was able to talk with his teammates two days after the accident, telling them, "I'll be able to pitch sooner than you".
Within two weeks, the Tigers were optimistic that Houtteman would be able to play again by June.
As a result of the injuries to Houtteman and Yankee star catcher Yogi Berra due to car accidents, Cleveland Indians playing manager Lou Boudreau banned his pl
Due to Tiger pitching injuries, and with many top players still in the military late in World War II (Houtteman was too young for the draft), he made his major league debut on April 29. At 17 years old, he was the youngest player in the American League in the 1945 season before being optioned back to Buffalo, where on June 20 he threw seven no-hit innings, facing only 22 batters in the process, but lost the game 2–0 in extra innings. He also appeared in 13 games as a relief pitcher, and finished his minor league season with no wins, two losses and an ERA of 5.33 in just over 25 innings pitched.
Houtteman was the youngest major leaguer in 1946 but played only one game for the Tigers that season, allowing eight runs and fifteen hits in eight innings. He spent most of 1946 in the minor leagues, finished at 16–13 and led the league in strikeouts. At the end of the season, Houtteman was named by six of the eight International League managers as the top pitching prospect in the league, leading the league in strikeouts with 150, pitching over 200 innings, finishing second in victories with 16, and amassing an 11–2 road record. Minor league third baseman Johnny Bero liked Houtteman's fielding ability so much that he called him "a fifth infielder."
Despite his newfound top prospect status Houtteman remained in Buffalo at the beginning of the 1947 season before being recalled to the Tigers in July. He was relegated to the bullpen for a time, and saw little action. But after Hal Newhouser, Fred Hutchinson and Dizzy Trout were used in two days, Tiger manager Steve O'Neill decided to start Houtteman against the Washington Senators for only the second start of his career. He tossed a five-hit shutout and Tiger general manager Billy Evans said, "In 40 years I've never seen a better pitching job by a first-year pitcher. We now know that Houtteman is really a big leaguer". He followed this with another five-hit victory against the Boston Red Sox, then pitched a three-hit shutout in September against the St. Louis Browns. He finished the season at 7–2 with a 3.42 ERA, seven complete games and two shutouts. His performance in 1947 caught the attention of New York Yankees star and future Hall of Famer Joe DiMaggio, who said of Houtteman and Bob Lemon, "They have more stuff and more pitching sense than any other young fellows I've seen come up in a long while".
The 1948 Detroit Tigers season began with Houtteman in the starting rotation. Things started off poorly, however, as Houtteman lost his first eight decisions. Two of the first five losses, though, were by one run, and he had little run support. The 0–8 start and lack of run support led to his being called "Hard Luck Houtteman" in the media. His first victory that year came against the Senators, in which he also drove in the winning run. After winning his next start, he defeated the Philadelphia Athletics allowing only five hits, and avoided another loss. But he then lost eight more games and finished the season at 2–16. His teammates and the media attributed this to bad luck rather than bad pitching, and still regarded him as a prime prospect. Newhouser said, "The kid has had nothing but bad luck since the season opened", while Fred Hutchinson said, "He shouldn't have lost more than three or four games had he gotten an even break". But his 4.66 ERA was only 0.06 higher than the major league average.
As 1949 spring training began, Houtteman was nearly killed. In Lakeland, Florida on March 10, while driving home from Florida Southern College, he crashed into a fruit truck fracturing his skull. Originally listed in critical condition (a priest stood by to administer the last rites in extremis), he recovered rapidly and was able to talk with his teammates two days after the accident, telling them, "I'll be able to pitch sooner than you". Within two weeks, the Tigers were optimistic that Houtteman would be able to play again by June. As a result of the injuries to Houtteman and Yankee star catcher Yogi Berra due to car accidents, Cleveland Indians playing manager Lou Boudreau banned his pl
Art Houtteman