The San Diego Padres selected Spangenberg in the first round, with the 10th overall selection, of the 2011 MLB Draft. Spangenberg signed with the Padres, receiving a $1.883 million signing bonus. He made his professional debut with the Eugene Emeralds and was promoted to the Fort Wayne TinCaps in July. In 72 games between both teams, he batted.316 with three home runs and 44 RBIs. Before the 2012 season, MLB.com rated Spangenberg as the 81st best prospect in baseball. in 2012 Spangenberg played for the Lake Elsinore Storm in 2012 where he hit.271 with one home run and 40 RBIs in 98 games, and Lake Elsinore and the San Antonio Missions in 2013 where he slashed.292/.346/.407 with six home runs and 51 RBIs in 130 games. He spent 2014 with the San Antonio Missions. He missed two months of the season in 2014 after suffering a concussion, but was named the Texas League Player of the Month for July after returning to the Missions. Spangenberg, who had primarily played second base in his minor league career, also moved around the field in 2014, making starts at third base and in center field. In 66 games for San Antonio, he batted.331 with two home runs and 22 RBIs.
San Diego Padres
The Padres promoted Spangenberg to the Major Leagues on September 1, 2014, receiving a start at third base and recording his first Major League hit, a two-run single. He hit a walk-off home run off Brad Ziegler of the Arizona Diamondbacks in his second Major League game. He played in 20 games in 2014, making starts at third and in left field. Spangenberg made the Padres' Opening Day roster in 2015 as a bench player, making occasional appearances at second and third. By June 2015, Spangenberg began to gain playing time at second base, due to the struggles of Jedd Gyorko. He suffered a knee injury in late June and went on the disabled list, returning in mid-August. For 2015, Spangenberg finished with a.271/.333/.399 batting line and 4 home runs in 108 games, with 48 starts at second base and 11 at third. Spangenberg was the starting second baseman on the 2016 opening-day roster, but he tore his quad in April and played in only 14 games that season. Jemile Weeks, and later Alexi Amarista and Ryan Schimpf, picked up most of the remaining time at second base. After competing with Schimpf for the starting third base job in spring training in 2017, Spangenberg was among the Padres' final roster cuts. He was recalled on April 25 after hitting.348 in El Paso while Schimpf struggled with the Padres. Spangenberg started slowly, but improved in the second half, putting up a.794 OPS with eight home runs after the All-Star break and claiming the third-base position as Yangervis Solarte transitioned to shortstop in August. He finished with a.264/.322/.401 batting line and 13 home runs in 129 games, with 86 starts at third base, 12 in left field, and 4 at second. In 2018, he hit.235 with 7 home runs and 25 runs batted in. He was designated for assignment on November 20 and released the next day.
Milwaukee Brewers
Spangenberg signed a one-year deal with the Milwaukee Brewers on January 4, 2019. He opened the 2019 season with the San Antonio Missions. On May 14, he was designated for assignment. On August 24, the Brewers selected Spangenburg's contract. In AAA with the San Antonio Missions, he led the PCL with 28 stolen bases while being caught four times, and batted.309/.378/.498.
Saitama Seibu Lions
On December 6, 2019, Spangenberg signed with the Saitama Seibu Lions of Nippon Professional Baseball.
