On March 4, 2008, Mercedes signed with the Detroit Tigers as an international free agent. On November 20, 2012, the Tigers added Mercedes to their 40-man roster to protect him from the Rule 5 draft.[1]
The Tigers promoted Mercedes to the major leagues on August 14, 2014.[2] Before being called up, Mercedes had a 4.33 ERA and a 1.33 WHIP in 41 appearances for the Triple-AToledo Mud Hens.[3] Mercedes made his major league debut on August 15, when he pitched two scoreless innings, allowing no hits or walks, and recording two strikeouts. On August 17, Mercedes was optioned back to the Toledo Mud Hens.[4] On December 11, Mercedes was designated for assignment by the Tigers.[5] On December 19, Mercedes cleared waivers and was sent outright to Triple-A Toledo.[6]
During the 2015 season, he split time between the Double-AErie SeaWolves and Triple-A Toledo Mud Hens. On December 23, 2015, the Tigers re-signed Mercedes to a minor league contract.[7] On March 23, 2016, Mercedes was released by the Tigers.
Guerreros de Oaxaca
On May 6, 2016, Mercedes signed with the Guerreros de Oaxaca of the Mexican League. In 35 appearances for Oaxaca, he posted a 5-2 record and 4.73 ERA with 21 strikeouts across 32+1⁄3 innings of relief. Mercedes was released by the Guerreros on July 7.
York Revolution
On April 5, 2017, Mercedes signed with the York Revolution of the Atlantic League of Professional Baseball. In 7 games for York, he compiled a 3.68 ERA with 8 strikeouts across 7+1⁄3 innings pitched. Mercedes was released by the Revolution on May 14.