Muno, 26, has just two hits in 22 plate appearances for the Mets this season, while batting .269 in Triple-A.
Ruben Tejada is currently on paternity leave, and Daniel Murphy is still on the disabled list, leaving the team short on middle infielders for the bench. Muno has played shortstop, second and third base this season.
Goeddell, 26, had a 1.96 ERA in 22 relief appearances for the Mets this season, with all five runs coming in two outings during May.
Terry Collins will now have six relievers in his bullpen.