Houston's No. 4 prospect, according to MLB.com, Foltynewicz was called up to the Major Leagues for his Major League debut and will pitch in the bullpen for the rest of season, though his future remains as a starter down the road.
"I'm just getting my chance to prove I belong here," he said. "It's been a long journey, four or five years in the Minor Leagues, and I've proven to everybody I deserve to be here. That's the big thing, just go out there and try to win for the team. I'm a big competitor, so I'm going to go out there and do as much as I can to help the team win."
Foltynewicz's parents, Gary and Cindy, were delayed getting to Houston from their home in Illinois, but he was expected to have his parents, his girlfriend and some friends in town to see him pitch.
"I can't really put words into what I'm feeling right now, but it's awesome," Foltynewicz said.
Foltynewicz, taken with the No. 19 overall pick in the 2010 First-Year Player Draft, went 7-7 with a 5.08 ERA at Triple-A Oklahoma City as a starter, striking out 102 batters in 102 2/3 innings with his high 90s mph heat.
"He's had basically four months of pitching in the rotation at Triple-A, and we feel like it's really been beneficial for him," general manager Jeff Luhnow said. "He's refined his offspeed stuff and has been able to work on a lot of different things. We're going to pitch him in the bullpen here for the remainder of the year, and that will give him an opportunity to get his feet wet at the Major League level and show us what he's got. He'll help us win some games."
Luhnow envisioned Foltynewicz pitching in the sixth, seventh or eighth and perhaps working multiple innings.
"We'll have to see how the manager wants to use him and how effective he is," Luhnow said. "If he ends up being a guy we can use in those critical late-game situations -- we have some good pitchers there now -- but if he adds to that depth there, that will be good."
Foltynewicz is unfazed by having to come out of the bullpen. He's done that on a number of occasions this year in Oklahoma City's tandem starting pitching rotation, where two "starters" throw in the same game.
"It's definitely going to be an adjustments at the big league level, but I relieved in Spring Training the whole time so I kind of got used to doing it there," he said.
Foltynewicz admits he has other hurdles to overcome, such as keeping his emotions in check on the mound when things don't go his way.
"That's been one of the biggest steps for me," he said. "I get competitive up there and put my heart on my sleeve, but I've learned you can't do that. You have to be level on the mound and I've been trying. I had a couple of [setbacks] early in the year, but other than that, I've been trying real hard to keep them in check."
The hard fastball has been one of the best in the system for years, and Foltynewicz is still trying to refine his offspeed pitches.
"I'm 100 percent confident in my changeup. and my curveball and slider are at the top of their game right now," he said. "I feel confident in all the pitches right now."
Foltynewicz is the fourth top prospect to be called up by the Astros this year, joining outfielder George Springer, first baseman Jon Singleton and outfielder Domingo Santana, who had only 13 at-bats with the Astros before being sent back down.
Foltynewicz was 14-4 with a 3.14 ERA in 27 starts at Class A Lexington in 2012, and last year he was a combined 6-3 with a 3.06 ERA in 30 games between Class A Advanced Lancaster and Double-A Corpus Christi.
"I've been at the grind since the age of 18," he said. "The support of my family and friends has been huge throughout. This journey, it's tough on them. A lot of people don't see it. It's tough on your parents, your friends, your girlfriend and all that, but other than that, just to have their support, you'll get through it."