He played in Major League Baseball (MLB) for the Cleveland Indians, Texas Rangers, New York Yankees, Tampa Bay Rays and Boston Red Sox.

A power pitcher, Kluber achieved high strikeout rates through a two-seam sinker and a breaking ball that variously resembled a slider and a curveball.

The San Diego Padres selected Kluber in the fourth round of the 2007 draft, and traded him to the Indians in 2010 as part of a three-team transaction.

On May 13, 2015, Kluber became one of 20 pitchers in major league history to strike out at least 18 batters in a nine-inning game, doing so versus the St. Louis Cardinals.

[1] While pitching for the school's baseball team, Kluber developed a stress fracture in his elbow due to overuse by his coach Don English, requiring surgery and the insertion of two screws.

[2] Kluber began to draw notice from coaches at Stetson University, when he pitched at the World Wood Bat Championships in Jupiter, Florida.

[3][4] As a freshman in 2005, Kluber performed as a relief pitcher, compiling a 2–2 win–loss record with a 7.82 earned run average (ERA) in 25 innings pitched.

[2][10] At the time of the trade, Kluber's minor league record was 18–24, and he was not ranked among the top thirty prospects in the Padres' farm system.

During a rain-induced bullpen session in May 2012, at the recommendation of Columbus pitching coach Ruben Niebla, Kluber first threw his two-seam fastball.

[1][15] Kluber was brought up from Columbus in August 2012 to replace starting pitcher Josh Tomlin in the Indians' rotation.

[16] Kluber began the 2013 season with Columbus, but received a promotion when Brett Myers suffered an elbow injury.

He posted back-to-back 14 strikeout games as Cleveland stayed in contention late in the season for a wild card spot.

[21] Kluber became the fourth Indians player to win the award, following Gaylord Perry, CC Sabathia, and Cliff Lee.

[22] On April 5 Kluber signed a guaranteed five-year extension with an additional two option years, for a team-friendly $38.5 million.

"[23] On May 13, 2015, Kluber struck out a career-high 18 batters over eight shutout innings against the St. Louis Cardinals, earning his first win of the 2015 season.

[26] Despite posting a 3.49 ERA and striking out 245 batters in 222 innings, Kluber suffered from poor run support for much of the 2015 season, finishing with only nine wins and an American League-leading 16 losses.

Kluber was named a member of the 2016 American League All-Star team on July 7, 2016, his first selection, as a replacement for an injured Marco Estrada.

[29] In Game 1 of the World Series against the Chicago Cubs, Kluber struck out nine batters in six-plus shutout innings.

[28] Though the Cubs won Game 7 and claimed the Series, Kluber's efforts help boost Cleveland's opportunities: he posted a 1.83 ERA in six postseason starts.

[32] On November 7, Kluber was announced by the BBWAA as a finalist for the 2016 American League Cy Young Award, along with Justin Verlander and Rick Porcello.

[37] On July 3, 2017, Kluber was named the AL Pitcher of the Month for June after he posted a 4–0 record, 43 IP, 1.26 ERA, 64 SO, 0.67 WHIP and 13.4 K/9 in six starts.

[39] On August 3, 2017, Kluber struck out 11 batters and gave up three hits in a 5–1 complete game win against the New York Yankees, making him the fourth pitcher ever to get eight or more strikeouts in 12 consecutive starts.

[41] Kluber hurled his third shutout of the season with 12 strikeouts on September 12, 2017, versus the Detroit Tigers, giving the Indians their 20th consecutive win.

He started Game 1 of the American League Division Series but was the losing pitcher after giving up three home runs in 42⁄3 innings against the Houston Astros.

[57] On December 15, 2019, Cleveland traded Kluber and cash considerations to the Texas Rangers in exchange for Delino DeShields Jr. and Emmanuel Clase.

[58] On July 26, 2020, Kluber made his Rangers debut during the shortened 2020 season but lasted just 1 inning after experiencing shoulder tightness.

He was subsequently diagnosed with a torn teres major muscle, sending him to the Rangers' injured list, thus ending his season.

He threw 71 of 101 pitches for strikes and struck out nine batters in a 2–0 win, with a third-inning walk to Charlie Culberson being the only blemish in an otherwise perfect game.

An MRI revealed that he had suffered a strain to the subscapularis muscle of his right shoulder, and was expected to miss two months of the 2021 season.

[87][88][89] His most dominant pitches are his two-seam sinker,[9][12][90] which he first learned in 2011 as a member of the Columbus Clippers,[11][91] and his breaking ball,[88][92] which variously resembles a slider and a curveball.