Miguel Socolovich signed with the Boston Red Sox as an international free agent in 2004. He did not play in 2005, after undergoing Tommy John surgery on his right elbow. He did not join the organization until 2006. He spent the rest of the season playing for the Gulf Coast League Red Sox. Socolovich moved up to Single-A the following year, playing for the Lowell Spinners and later the Greenville Drive.
He began the 2012 season playing in Triple-A with the Norfolk Tides before earning his first call-up to the major leagues on July 14, 2012. At the time of his call-up, he had a 1.95 earned run average in 24 games with Norfolk. He made six appearances with the Orioles before being designated for assignment on August 14. He recorded a 6.97 ERA in innings during his time in Baltimore. With Norfolk that year, he held a 4−0 win−loss record with a 1.90 ERA in 28 appearances and 52 innings pitched, striking out 52 and walking 14 while holding opponents to a.179 batting average against.
Chicago Cubs organization
On August 23, 2012, Socolovich was claimed off waivers by the Chicago Cubs, who optioned him to the Iowa Cubs, their Triple-A affiliate in the Pacific Coast League.
Hiroshima Toyo Carp
On November 15, 2012, the Hiroshima Toyo Carp of Nippon Professional Baseball agreed to terms with Socolovich to bring him to Japan.
On November 21, 2013, Socolovich signed a minor league contract with the New York Mets.
St. Louis Cardinals organization
He joined the St. Louis Cardinals organization on November 12, 2014, who optioned him to the Triple-A Memphis Redbirds of the PCL. He began the season with a -inning scoreless streak. During that streak, he walked eight, struck out nine, and allowed five hits in fourteen at bats. The Cardinals called Socolovich up for the first time in 2015 on April 30. He earned his first major league victory on May 3, 2015, after pitching a scoreless 14th inning against the Pittsburgh Pirates. He earned his second victory the following night, against the Chicago Cubs, who would finish two games and three games, respectively, behind first-place St. Louis in the National League Central division. The Cardinals optioned him back to Memphis, where he posted a 2.48 ERA and an.165 opponent average and 0.92 WHIP in IP for the season, and recalled him September 2. At the major league level in 2015, he finished with a 1.82 ERA and 4−1 record. Beginning the 2016 season at Memphis, Socolovich authored an 11-inning scoreless streak over nine appearances through June 21. The Cardinals recalled him to St. Louis on July 19 after third basemanJhonny Peralta went on the disabled list. His pitch arsenal includes a fastball, changeup, and slider. At Memphis, Socolovich was 2−5 with a 2.79 ERA in 35 games, inducing 40 strikeouts in IP. Socolovich was designated for assignment on May 27, 2017. He was 0-1 with one save in 15 appearances, striking out 14 in 18 innings. He elected free agency on November 6, 2017.
Atlanta Braves
On January 26, 2018, Socolovich was invited to spring training with the Atlanta Braves. His contract was purchased by the Braves on March 30, 2018. He was later designated for assignment on April 2 in order to make room for Aníbal Sánchez on the active roster. Socolovich cleared waivers and was outrighted to the Gwinnett Stripers. He had his contract purchased again on April 21. He was outrighted to the Gwinnett Stripers for the second time on April 26. He was again called up the Braves on May 30, and outrighted for the third time on June 3. He elected free agency on October 2, 2018.
