Grady Sizemore's journey in Major League Baseball began when he was drafted by the Montreal Expos in the third round of the 2000 MLB Draft. However, it was with the Cleveland Indians that he would spend the majority of his career, after being traded to the team in 2002. Sizemore quickly rose through the ranks of the Indians' minor league system, showcasing his potential as a dynamic outfielder.

Sizemore made his MLB debut with the Indians in 2004. By the following year, he had secured a regular spot in the lineup, playing center field. Known for his athleticism and speed, Sizemore quickly became a fan favorite. His ability to cover ground in the outfield and his prowess on the base paths were complemented by his offensive skills. In 2005, he hit .289 with 22 home runs and 81 RBIs, establishing himself as a key player for the Indians.

The 2006 season saw Sizemore's performance reach new heights. He played in all 162 games, a testament to his durability at the time, and posted a .290 batting average with 28 home runs, 76 RBIs, and 22 stolen bases. His efforts earned him a spot on the American League All-Star team, and he finished 11th in the MVP voting. Sizemore's combination of power and speed was rare, and he became one of the few players in MLB history to record 20 home runs, 20 triples, and 20 stolen bases in a single season.

Sizemore continued to excel in 2007, once again playing in every game of the season. He hit .277 with 24 home runs, 78 RBIs, and 33 stolen bases, helping the Indians reach the postseason. His performance in the playoffs was instrumental in the team's run to the American League Championship Series, where they were ultimately defeated by the Boston Red Sox. That year, Sizemore earned his first Gold Glove Award, recognizing his defensive excellence in center field.

In 2008, Sizemore had one of the best seasons of his career. He hit 33 home runs, drove in 90 runs, and stole 38 bases, earning his second consecutive Gold Glove and a Silver Slugger Award. He was once again named an All-Star and finished 10th in the MVP voting. Sizemore's ability to contribute both offensively and defensively made him one of the most exciting players to watch in the league.

Unfortunately, Sizemore's career was soon derailed by a series of injuries. Starting in 2009, he began to experience a string of health issues, including surgeries on his elbow, knee, and back. These injuries severely limited his playing time and effectiveness on the field. From 2010 to 2013, Sizemore appeared in only 104 games, struggling to regain his previous form.

After missing the entire 2012 and 2013 seasons, Sizemore attempted a comeback with the Boston Red Sox in 2014. He made the team's Opening Day roster and hit a home run in his first game back. However, his time with the Red Sox was short-lived, and he was released mid-season. Sizemore then signed with the Philadelphia Phillies, where he played the remainder of the 2014 season and part of 2015.

Despite his efforts to return to his former level of play, Sizemore's career never fully recovered from the injuries that plagued him.