Feliz made his Major League debut on Sunday, pitching a scoreless ninth inning.
"It was a great opportunity for him to get his feet wet in the big leagues," Astros manager A.J. Hinch said. "The confidence that he should go back to the Minor Leagues with is good.
"We saw really good stuff. The same fastball that we saw in Spring Training. I thought his calmness on the mound coming into his first big league game was exceptional."
Feliz allowed a double to Carlos Sanchez, the No. 9 hitter, then retired Adam Eaton on a flyout, Melky Cabrera on a flyout and struck out Adam LaRoche, who had homered in the seventh inning off Jake Buchanan.
"When you get Eaton, when you get Cabrera, when you get LaRoche in your first outing at the top of their order -- they're at the top of the order for a reason -- that should give him a lot of confidence and a lot of positive vibes when he comes back here," Hinch said.
Feliz, 21, is ranked as the Astros' No. 5 prospect and was called up from Corpus Christi on Friday.
Richard Dean is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.