Through June, Granderson ranked first among American League (AL) outfielders in triples (14), third in doubles (22), tied for fourth in runs (58) and tied for 10th in homers (11) with a .289 batting average in the 2007 season. Although Granderson was not listed on the 2007 All-Star Game ballot, due to the Tigers' decision to put Gary Sheffield as an outfielder on the ballot, he still received 376,033 write-in votes, the most write-in votes for any player. Granderson was named the AL Player of the Week on July 16, the first time he had won the award, as he hit .500 (8 for 16) with two doubles, a triple, and a home run during that week. Granderson slugged .938, drove in two runs, scored seven runs, and had fifteen total bases during Detroit's four-game series against the Seattle Mariners.
During the 2007 season, Granderson accumulated 23 triples, which led all of baseball. The American League and Detroit Tigers record is 26 triples, a feat achieved by the all-time triples king, Sam Crawford, in 1914. Granderson is the first player since 1949 to manage at least 23 in a single season. Only ten of his triples were at home despite the fact Comerica Park has seen more triples since it opened in 2000 than any other ballpark in baseball. Granderson joined the 20-20-30-20 club, having more than 20 triples, 20 home runs, 30 doubles, and 20 stolen bases. The last player to accomplish the feat was Wildfire Schulte in 1911. Granderson's 23 triples were as much or more than six entire teams managed in 2007; the Chicago White Sox, Cincinnati Reds, Los Angeles Angels of Anaheim, Oakland Athletics, Seattle Mariners and St. Louis Cardinals all had no more than 23 team triples.
Prior to the start of the 2008 season, the Tigers signed Granderson to a five-year, US$30.25 million contract with a club option for 2013. Granderson continued hitting well during the 2008 regular season, finishing with a .280 batting average, 13 triples and 22 home runs. He continued to improve his plate discipline, striking out only 111 times (versus 141 in 2007 and 174 in 2006) and drawing a career-high 71 walks. During August, he hit six triples, including two in consecutive innings during a game against the Texas Rangers.
With the Tigers failing to make the playoffs in 2007 and 2008, TBS employed Granderson as a commentator alongside Cal Ripken, Jr., Dennis Eckersley and Frank Thomas for its coverage of the 2007 and 2008 postseasons.