He split 2012 between the Single-A Peoria Chiefs and the Low-A Boise Hawks, accumulating a 4-2 record and 3.58 ERA between the two teams.

In 2013, he played for the Single-A Kane County Cougars, pitching to a 4-7 record and 3.92 ERA with 77 strikeouts in 103.1 innings of work.

He split the next year between the High-A Daytona Cubs and the Double-A Tennessee Smokies, registering a 6-10 record and 4.15 ERA across 25 appearances.

After recording a 3.41 ERA in 36 games in Iowa, Peña was called selected to the 40-man roster and promoted to the major leagues for the first time on August 19, 2016.

[2] He made his debut that day, pitching a scoreless innings and notching his first major league strikeout, punching out Daniel Descalso of the Colorado Rockies.

Peña did not participate in the postseason, but was on the 40-man roster at the time the Cubs won, earning him his first World Series ring.

[7] On July 12, 2019, Peña pitched seven no-hit innings, helping the Angels throw a combined no-hitter against the Seattle Mariners.

[16] On February 2, 2025, Peña signed with the Uni-President Lions of the Chinese Professional Baseball League.