Hector Felipe Santiago (born December 16, 1987) is an American professional baseball pitcher for the Acereros de Monclova of the Mexican League.

[2] He made his professional debut with the Rookie-level Bristol White Sox of the Appalachian League that summer, going 1–1 with a 1.65 ERA in 17 relief appearances.

[3][4] While playing for Bristol, Santiago also befriended Nate Jones, and the pair rose through the White Sox's farm system at the same pace.

For the 2009 season, Santiago played for the High-A Winston-Salem Dash, pitching to a 4-4 record and 3.88 ERA with 66 strikeouts in 58.0 innings of work.

[7] Santiago made his MLB debut on July 6, 2011, pitching a perfect ninth inning against the Kansas City Royals.

On April 7, 2012, Santiago earned his first career save by striking out Elvis Andrus to seal a 4–3 victory for the White Sox.

On May 8, Santiago earned his first career win during a 5–3 victory over the Cleveland Indians, pitching one inning yielding two hits and striking out one.

[20] Santiago spent the majority of the season in the White Sox bullpen, logging a 4.41 ERA in 102.0 innings pitched across 49 appearances.

[23] He played seven games for Charlotte, going 1–4 with a 5.84 ERA in the process,[3] before he was called up to Chicago on August 6, replacing an injured Manny Bañuelos.

[31] Santiago's resume approach did not garner any more team offers for the remainder of the 2020 season, or in time for 2021 spring training, and he spent the winter playing for Puerto Rico in the 2021 Caribbean Series.

On April 30, the Seattle Mariners called Santiago and asked if he could make a start for their Triple-A team, the Tacoma Rainiers, on May 8.

[32] On May 27, the Mariners selected his contract and promoted Santiago to the majors, where he was meant to bolster a bullpen that had been depleted by injury and COVID-19.

[33] On June 27, Santiago became the first MLB player ejected from a game as part of new policies banning the controversial "sticky stuff" that pitchers used to enhance their grip.

[35] Only two days after returning from that suspension, Santiago was suspended for an additional 80 games without pay following a positive test for exogenous testosterone, considered by MLB to be a performance-enhancing drug.

He told reporters that his doctor in Puerto Rico had suggested that he undergo hormonal replacement therapy for an undisclosed medical condition, but he did not contest the suspension.

Santiago played for the Puerto Rican national team in the 2017 World Baseball Classic where he won a silver medal.