It's no secret the Astros needed to add a player to help their undermanned outfield, which has been decimated by injuries to Dexter Fowler, George Springer and Alex Presley. And they believe they had a surplus of starting pitchers, in addition to the depth in the system among right-handed starters.
"We've got guys all the way up and down the system," general manager Jeff Luhnow said. "Our pitching coaches have done a terrific job of not only developing these guys, but starting with here in Houston with the step forward a lot of Major League pitchers have taken this year.
"The same thing is going on in the Minor Leagues, and we feel good about what our pitching coaches have done and the way our trainers have kept them healthy. It's one of those areas that could very easily, with one or two injuries, go from a strength to a weakness. We're taking a calculated gamble in this, and it's the right thing to do."
The Astros on Wednesday traded Cosart, utility player Enrique Hernandez and Minor League outfielder Austin Wates to the Marlins for outfielder Jake Marisnick, Minor League third baseman Colin Moran -- one of Miami's top prospects -- and a 2015 Competitive Balance pick.
It was the third time in a year the team traded a young starter, sending Bud Norris to the Orioles last July and trading Jordan Lyles to the Rockies in the winter in the Fowler deal. That's a sign of the faith the club has in some of the young arms coming up, including Brady Rodgers, Alex White, Asher Wojciechowski, Lance McCullers Jr., Vincent Velasquez, Josh Hader and others.
"We have to be very careful in letting go of that pitching depth," Luhnow said. "We let Lyles go and we got Fowler and we feel pretty good about that trade at this point. In letting Cosart go, we're going to expect both of these players [Marisnick and Moran] are going to make it to the big leagues and contribute. That would be a win for us."
Luhnow said repeatedly leading up to the Trade Deadline the Astros had six quality starters, including right-hander Brad Peacock. He's expected to rejoin the rotation Wednesday in Philadelphia to take Cosart's spot after a stint in Triple-A.
Astros starters have a 4.07 ERA, which ranks 10th in the American League. They finished last year ranked 13th in starters' ERA at 4.72
While the overall numbers aren't going to blow anyone away, the Astros' rotation has been doing some pretty impressive work lately. Here's how it stacks up heading into Tuesday's game against the Phillies:
LHP Dallas Keuchel (10-7, 2.97 ERA): The lefty had to scratch and claw to make the rotation out of Spring Training, but he's emerged as the staff ace and made a run at the All-Star Game. As the Trade Deadline approached, Luhnow told teams Keuchel wasn't available. He threw his fourth complete game Wednesday, which leads the AL and ranks tied with Clayton Kershaw for first in the Majors. He's the first Astros pitcher with at least four complete games in a season since Roy Oswalt in 2005, and first lefty since Randy Johnson, who had four in 11 starts with the club in 1998.
What's more, Keuchel has pitched at least eight innings in six starts this year -- the most since Oswalt in 2008.
RHP Peacock (3-7, 4.93 ERA): Peacock began the season in the rotation, but didn't get his first win until his 10th start on May 18 against the White Sox. Prior to getting sent down after his July 23 start at Oakland, Peacock had struggled with an 8.40 ERA in his previous four starts. Still, the club still sees potential in Peacock, who went 2-3 with a 3.71 ERA in 11 starts from April 20-June 27, to feel comfortable trading Cosart and giving him another shot.
RHP Collin McHugh (4-9, 3.32 ERA): McHugh hasn't won since June 3, going 0-6 with a 4.20 ERA in his past eight starts. He hasn't pitched poorly in that span for the most part, allowing three earned runs or fewer six times in those eight starts. He's gone at least six innings in five of his last six starts and is averaging 10.6 strikeouts per nine innings, with a franchise record of least four strikeouts in each of his first 16 starts with the team.
LHP Brett Oberholtzer (4-7, 4.17 ERA): The lefty began the year in the rotation but was sent down after going 0-6 in his first seven starts. He spent the next couple of months bouncing between Triple-A Oklahoma City and Houston, pitching well each time he came back up. He held the Blue Jays to two runs and six hits in seven innings Saturday and has gone at least six innings in his last nine Major League starts. He's 4-1 with a 3.08 ERA in his last eight outings and has solidified his spot in the rotation.
RHP Scott Feldman (5-8, 4.13 ERA): The veteran of the bunch, Feldman threw his third career complete game on Sunday by holding the Blue Jays to one run and eight hits. He has posted a quality start in six of his last eight outings, and has not allowed more than three earned runs in 11 of his last 14 starts. He's 1-2 with a 3.49 ERA in his last four starts. He's been a valuable leader among the starting corps.