- For the article on the Mexican progressive rock musician, see Carlos Beltrán (musician)
Beltrán made his major league debut in 1998, playing 14 games with the Kansas City Royals. In 1999, he won a job in spring training as the Royals' starting center fielder and leadoff hitter. By mid-summer, he was displaying surprising power and moved to the #3 slot in the batting order, and he won the American League Rookie of the Year award.
Injuries caused Beltrán to miss part of the 2000 season and he slumped to .247, losing his center field job to the popular Johnny Damon. After Damon was traded to the Athletics following the season, Beltrán regained his job and recaptured his rookie form, batting .306 with 24 home runs and 101 RBI in 2001, and followed up with .273, 29, 105 in 2002, and .307, 26, 100 in 2003.
Because Kansas City is a small-market club, and Beltrán is represented by agent Scott Boras, trade rumors followed Beltrán through the 2003 and 2004 seasons, as the end of his contract neared and the two sides failed to negotiate a long-term deal. During a press conference following an interleague doubleheader loss to the last-place Montreal Expos, Royals general manager Allard Baird told reporters that he was preparing to dismantle the team and rebuild it for the 2005 season. While Beltrán's name was not mentioned specifically by Royals management, the high-profile player, who was already eligible for free agency following the season, was considered the most likely to garner interest from other teams. On June 24, Beltrán was traded to the Houston Astros in a three-team deal, with the Oakland Athletics getting closer Octavio Dotel and the Royals picking up three prospects.
Beltrán was selected to the American League starting outfield for the 2004 All-Star Game, but he was initially denied a place in the game because of his trade to the National League. After NL starter Ken Griffey, Jr. went on the disabled list just before the All-Star break, Beltrán was named his substitute.
In the 2004 MLB playoffs, Beltrán tied Barry Bonds's single postseason record with 8 home runs. In Game 5 of the NLDS against the Atlanta Braves, he had two home runs, and he had one in each of the first four games of the NLCS against the St. Louis Cardinals, including a game-winner in Game 4. This gave him five straight playoff games with a home run, a new record.
Beltrán became a free agent for the first time after the 2004 season and was touted as the biggest free agent on the market. After the New York Yankees decided against pursuing him, he signed a 7 year - $119 million contract with the New York Mets, the biggest contract in Mets history. It was also only the tenth contract in Major League Baseball history to be worth more than $100 million.
Reaction to the signing was met with enthusiasm by many, though some felt the Mets may have overpaid. Beltrán is what scouts call a "five-tool player," with good fielding skills, a good throwing arm, ability to hit for average, power, and steal bases. He bolsters an already potent Mets roster that includes future hall of famer Mike Piazza, young sensations Jose Reyes and David Wright, and recent free agent signing Pedro Martinez. At 27, he is thought to be entering the prime years of career. However, critics have expressed that his skills may be overrated. They cite that prior to the 2004 season, he never hit 30 or more home runs and that he is only a career .280 hitter. Those critics may be correct, too. Beltran has not even come close to reaching the numbers he posted in 2004 with his new team. It should be noted, however, that Beltran spent most of the 2004 season in hitter friendly ballparks, as opposed to the pitcher friendly Shea Stadium. Nevertheless, Beltrán has failed to live up to the hype and some regard his signing as a mistake.