Daniel attended Damien High School in La Verne, California along with running back Ian Johnson, former NFL wide receiver Freddie Brown, and soccer forward Chukwudi Chijindu.

[4] After placing pitcher Evan Meek on the 15-day disabled list with right shoulder tendinitis, the Pirates called Moskos up to the majors for the first time on April 30, 2011.

On that same night, he made his Major League debut, pitching one scoreless inning in relief against the Colorado Rockies.

Less than a week later on May 28, Moskos was recalled to Pittsburgh due to Joe Beimel going on the 15-day disabled list with shoulder tightness.

[5] He made 16 appearances down the stretch for the Triple-A Charlotte Knights, recording a 4.43 ERA with 21 strikeouts and 2 saves across 20+1⁄3 innings pitched.

On March 1, 2016, Moskos signed a minor league contract with the San Diego Padres organization.

He made 53 appearances out of the bullpen for the Triple–A El Paso Chihuahuas, compiling a 5–2 record and 3.39 ERA with 47 strikeouts over 61 innings pitched.

[14] On November 27, 2024, the Miami Marlins hired Moskos to be the team's major league pitching coach.