The got even darker when word spread that Esteban was having an affair with Jenni's daughter Chiquis.
Both parties denied the allegations, but whatever Esteban did was harsh enough for Jenni to cut ties with him for good.
Loaiza moved to a big league club in 1995, making his major league debut on April 29, 1995, for the Pirates against the Philadelphia Phillies.
His early season troubles reached a nadir on April 29 when he gave up 10 runs in two innings to the Kansas City Royals, who had the worst record in baseball at the time; the game was not official since it was later rained out, or his statistics would have been even worse.
Loaiza's poor performance was at least partly due to injury, as he seemed to have very little velocity on his fastball early in the season (throwing it at as little as 82–83 mph) and was placed on the disabled list with back and shoulder problems on May 2.
Considered for the Cy Young Award, Loaiza finished second behind Roy Halladay, ahead of Pedro Martínez and Tim Hudson. Loaiza's 21 wins in 2003 are tied for the most ever in a season for a Mexican pitcher; Fernando Valenzuela won 21 games in 1986.
He did not perform well in New York and was moved to the bullpen during the regular season.
The Pirates traded him to the Texas Rangers on July 17, 1998, for Todd Van Poppel and Warren Morris.
He spent the next two seasons with Texas, pitching both as a starter and a reliever for the Rangers.Traded again, to the Toronto Blue Jays by the Rangers on July 19, 2000 for Michael Young and Darwin Cubillán, he pitched with the Blue Jays through 2002.After signing with the Chicago White Sox as a free agent, Loaiza enjoyed a career season in 2003, leading American League pitchers in strikeouts (207), and was second in wins (21) and strikeouts per nine innings (8.23); third in ERA (2.90), and sixth in innings pitched (226.3). Jenni Rivera's ex Esteban Loaiza has a new girlfriend.The 42-year-old baseball pitcher is dating singer Cristina Eustace.He went 12–10 with a 3.77 ERA for the Nationals in 2005.