Through four starts, Gallagher is 2-1 with a 1.93 ERA. He has notched 25 strikeouts to five walks in 23 1/3 innings, holding opponents to a .188 average against.
"He's only 22 years old and we have to keep that in mind, but he has really come of age," Cubs Assistant General Manager Randy Bush said of Gallagher. "He's got an outstanding fastball that he locates well and he's shown us that power-type curveball that he can throw.
"He's a guy that's going to help us in the big leagues at some point this year and he's going to have a long career as a major league pitcher," added Bush.