"I think coming up here and getting some playing time means they like me," Sappelt said. "They want me to show them what I can do. That's why they got me in a trade. I have to take advantage of all my opportunities."
After sweeping three games from the Pirates in Pittsburgh, the Cubs have won four straight games on the road for the first time since July 31-Aug. 4, 2011. Their four-game winning streak matches a season high.
Manager Dale Sveum said the team has started to understand the real possibility of a 100-loss season. The Cubs need to go 8-13 over their final 21 games to avoid that mark.
"That's the goal. It's the talk now," Sveum said. "Obviously, they're responding right now."
Sappelt's RBI double in the second inning off Astros starter Dallas Keuchel and two-run double in the seventh off reliever Hector Ambriz helped the Cubs move closer to avoiding statistical infamy. He also scored the go-ahead run in the sixth inning on a wild pitch from reliever Fernando Rodriguez.
"We count down every day our magic number to not get 100 [losses]," Sappelt said. "We definitely have that in the back of our minds. We just want to keep playing hard."
Chris Volstad allowed one run over five innings to earn his third win in his last four starts. Since returning from Iowa and giving up two runs over seven innings against the Dodgers on Aug. 4, Volstad's ERA is 4.35. That isn't spectacular, but it's a far cry from the numbers he posted early in the season.
"I feel like ever since I've come back, I've been a different pitcher, starting with that L.A. game," Volstad said. "I feel good."
Sveum said before the game that he wanted to see Volstad pitch into the sixth or seventh inning, but the Astros worked a few long at-bats to raise the right-hander's pitch count.
Astros outfielder Justin Maxwell tripled to open the fourth and scored on Jason Castro's single. Leadoff man Jimmy Paredes tripled to start the fifth inning, and Volstad walked Fernando Martinez and, after recording two outs, also walked Castro to load the bases. Volstad got Matt Dominguez to ground out to escape the jam.
"That's what you're looking for -- to get out of that mess," Sveum said. "That was a battle that he won. That's what you want to see. He ended up getting out of that and battling his butt off and making the pitch when he had to make it."
Volstad wanted to go longer in the game, too, but he was satisfied with making it through the fifth without any more damage on the scoreboard.
"Leadoff triple, that has to score 98 percent of the time I would guess," Volstad said. "I was out there just trying to locate pitches, and the defense did a great job."
At 99 pitches, Volstad left the game after the fifth. He allowed four hits, striking out four and walking five. The last time Volstad walked at least five batters was Sept. 13, 2009. His ERA is down to 5.99 after sitting at 7.46 in the middle of May.
Relievers Miguel Socolovich, James Russell, Jaye Chapman and Shawn Camp combined to hold the Astros to a hit and a walk over their three innings. Socolovich and Chapman were both recalled after rosters expanded.
Carlos Marmol pitched the ninth to record his 19th save and 18th in a row. His ERA since May 2 is 0.52.
Sappelt understands that he needs to seize his opportunity to improve his chances at being a part of the team's future plans.
He certainly did that in the seventh inning after Josh Vitters hit into a double play with the bases loaded, belting a line drive off the wall in left-center field and giving the Cubs two insurance runs.
"When people get their call, they have to step up," Sappelt said. "That's what they're trying to figure out now as an organization -- what we have and what they've got to do in the offseason."
"We got the double play and it was executed perfect, and the next guy got the big hit," Astros interim manager Tony DeFrancesco said. "We were close to keeping that game close."
The Cubs are now 1-3 in Houston this season after being swept by the Astros from May 21-23.