Mario Santiago was drafted in the 16th round (472nd overall) of the 2005 MLB draft by the Kansas City Royals. Having never caught on with the club, he moved on to the KBO in Korea in 2012, joining the SK Wyverns. He won six games and notched an ERA of 3.40 in 18 games. His stint in Korea lasted just the one season.
After signing a minor league deal with the Los Angeles Dodgers, Santiago joined the Puerto Rico national team for the 2013 World Baseball Classic. He was instrumental in his country’s defeat of Japan in the semifinals, pitching 4 ⅓. Innings of shutout ball. Unfortunately, this brief triumph was also the cause of elbow discomfort, and the next month he had season-ending Tommy John surgery. His next baseball action was not until the 2014 Winter League in Puerto Rico.
Santiago joined the Tigers on March 16, 2015, becoming the fifth foreigner on the roster. With all four regular import players taking home hardware in 2014 (Randy Messenger – most wins & strikeouts, Seung-hwan Oh – most saves, Matt Murton – top average, Mauro Gomez – most RBIs), it seemed unlikely that he would get any playing time on the top squad. However, his strong play on the farm combined with a slow start to the season for Messenger meant that he got called up to the parent club on May 15.
In his debut start that day at Nagoya Dome against the Chunichi Dragons, he went 7 strong innings, surrendering just a single run. He ended up as hero of the game. His second start (May 22 at Koshien vs. the DeNA BayStars) was not as impressive. He was unable to get through the fifth inning, and ended up not being involved in the decision (Hanshin lost). He got just one more start (May 28 vs. Eagles, another no-decision) before Messenger was declared fit and ready to return to duty.
Santiago was sent down to the farm and played out the season there before leaving Japan on October 6. The club did not renew his contract in 2016.
A Fifth Foreigner? Tigers Sign Santiago (March 16, 2015)