Justin Smoak's journey through Major League Baseball began when he was selected by the Texas Rangers as the 11th overall pick in the 2008 MLB Draft. Known for his power-hitting abilities and solid defensive skills at first base, Smoak quickly became a player to watch as he progressed through the minor leagues. His major league debut came on April 23, 2010, with the Rangers, marking the start of a decade-long career in the big leagues.

Smoak's time with the Rangers was relatively short-lived. In July 2010, he was traded to the Seattle Mariners as part of a deal for pitcher Cliff Lee. This move to Seattle provided Smoak with the opportunity to establish himself as a regular in the Mariners' lineup. Over the next few seasons, he displayed flashes of his potential, particularly with his power at the plate. However, consistency eluded him, and he struggled with batting average and strikeouts during his tenure with the Mariners.

In 2014, Smoak was claimed off waivers by the Toronto Blue Jays, a move that would prove to be a turning point in his career. With the Blue Jays, Smoak found a more stable footing and began to refine his approach at the plate. The 2017 season was a standout year for him, as he hit a career-high 38 home runs and was selected to his first All-Star Game. This performance solidified his role as a key player in the Blue Jays' lineup and earned him recognition as one of the league's top power hitters that year.

Smoak's tenure with the Blue Jays lasted until the end of the 2019 season. During his time in Toronto, he became known not only for his power but also for his improved on-base skills and defensive reliability at first base. His ability to switch-hit added an extra layer of value to his game, making him a versatile option in the batting order.

Following his stint with the Blue Jays, Smoak signed a one-year contract with the Milwaukee Brewers for the 2020 season. However, his time with the Brewers was brief, as he was released in September 2020 after struggling to find his form at the plate. Shortly thereafter, he signed with the San Francisco Giants, but his tenure there was also short-lived, and he did not appear in any games for the team.

After his MLB career, Smoak took his talents overseas, signing with the Yomiuri Giants of Nippon Professional Baseball (NPB) in Japan for the 2021 season. This move marked a new chapter in his professional career, allowing him to continue playing at a high level while experiencing a different baseball culture.

Throughout his career, Justin Smoak was known for his power-hitting capabilities and his steady presence at first base.