He struck out 10 in a two-hit shutout of the Orioles on August 16. Tanana's 3.58 ERA would be his lowest ever for the Tigers, save for the 20 starts he made for them in 1985. He had a 10–14 record, striking out 147 batters in innings. He became a free agent after the season but re-signed with the club a week later. Entering his 18th major league season in 1990, Tanana had won 198 games. He gave up five runs in seven innings on April 28, against the Milwaukee Brewers, but still picked up the win, the 200th of his career. The season saw him struggle, though—he had a 6.47 ERA through July 28, prompting the Tigers to re-sign Walt Terrell to replace him in the rotation. It was during this time that Tanana got the only save of his career, inducing Oscar Azócar to hit a foul pop-up and stranding a runner on second in the 14th inning of a 6–5 triumph over the Yankees August 2. He rejoined the rotation August 25 and posted a 2.44 ERA for the remainder of the year. In 34 games (29 starts), he had a 9–8 record, a 5.31 ERA, and 114 strikeouts in innings pitched. Following Jack Morris's departure via free agency in 1991, Tanana became the first pitcher besides him to make an Opening Day start for the Tigers since 1979, also the last year Tanana had made an Opening Day start. He gave up four runs in five innings against the Yankees, leaving with the game tied, but the Tigers beat New York 6–4. He threw a shutout against the White Sox April 18, then threw another shutout against the Angels June 7. Also, June 18, he came within one out of throwing another shutout but left after giving up two straight singles in the ninth; Mike Henneman finished a 2–0 victory over Oakland. On September 27, he became the last player to throw a pitch in the history of Memorial Stadium, allowing one run in a complete game, 7–1 victory over the Orioles. He made 33 starts for the Tigers in 1991, posting a 13–12 record, a 3.77 ERA, and 107 strikeouts in innings pitched. Tanana posted a 7.07 ERA in his first six starts of the 1992 season, then had a start skipped after May 7. Used in relief May 12, he picked up the win