"Those are generally pitch execution," manager A.J. Hinch said, "but there's also the other side. They've got pretty good players."
Feliz managed to get the next two outs before allowing singles to Tim Beckham and Luke Maile, which ended his night. He was relieved by Sipp.
"That's a little more unlucky," Hinch said.
Feliz's struggles lately have seemingly come in spurts. While the 23-year-old has looked as dominant as any pitcher on the roster in some games, he's also allowed some big innings.
And while Feliz's struggles Sunday didn't help, the true dagger came on Sipp's second pitch, when Corey Dickerson blasted a three-run shot over the right-field wall, giving Tampa Bay a commanding 9-3 lead.
Giving up home runs in limited innings has been the story of Sipp's 2016 campaign. The only left-hander in the Astros' bullpen has allowed 12 in 35 innings, with five of those coming in his last seven games.
"We're trying to work with his delivery," Hinch said. "Today, they were saying his breaking ball wasn't breaking as much. His fastball leaks over the plate. Those are all bad signs for him."
Having just signed him to a three-year, $18 million deal in the offseason, Sipp's struggles put the Astros in a tough position, especially considering the club is in the midst of a Wild Card race. They're three games behind Baltimore for the second AL spot after Sunday's loss.
"Obviously, I want to try and find a pocket where it's safe for [Sipp] to come in and work on what he's been working on without the game on the line," Hinch said. "Today, at 6-3, the game was still close. He's got a perfect pocket for 'em. He can get those guys out. Execution wasn't his best today."
Jordan Ray is a reporter for MLB.com based in Houston. This story was not subject to the approval of Major League Baseball or its clubs.