A stone-faced and shell-shocked Brett Oberholtzer didn't hit New York's Alex Rodriguez with the pitch that got the lefthander ejected in the second inning Saturday. The actual impact of the inside throw, which directly followed the second long homer of the day Oberholtzer allowed, was a public service announcement: The Astros need a quality starting pitcher.

They're focusing on one in trade talks, too.

"It certainly is one of those things we talk about, probably more so than other areas," Astros general manager Jeff Luhnow said last week.

Trade season is arriving with roughly a month to go before the July 31 non-waiver deadline, and the Astros are doing their scouting homework on 2015's usual suspects: Philadelphia ace Cole Hamels, Cincinnati righthanders Johnny Cueto and Mike Leake, Oakland lefthander Scott Kazmir, Milwaukee righthanders Matt Garza and Kyle Lohse and Chicago White Sox righthander Jeff Samardzija.

The second wild card spot keeps teams in the race longer, and some clubs don't want to be the first to sell and wave the white flag. But as one general manager said, selling early allows a premium be charged for a player whom a team gains for three regular-season months - July, August and September - rather than just the final two as is the case with deadline deals.

When the market does take off, the Astros seem to have little choice but to deal. They have a division lead to protect, a plethora of young players they could move and a clear opening for a pitcher who could pair with Dallas Keuchel in the first two games of a playoff series.

"Obviously, there's been a lot of talk about our rotation; we've got some youth in our rotation," manager A.J. Hinch said. "We've got different styles. We've certainly had performances at different times. Again, I trust our guys. I like the guys we have, and if there's an upgrade that gives us a push then we'll address it accordingly. But my job is to believe in getting the most out of the players that we have."

Adding a reliever, even with an upgraded bullpen, is a secondary goal to a starter.

Collin McHugh and the rehabbing Scott Feldman remain quality rotation pieces, but there's a need beyond them that young pitchers Lance McCullers and Vince Velasquez probably can't fill because of developmental innings limits.

"(I'm hopeful for a trade based on) what we're doing right now and the position that we're in," Keuchel said before Saturday's 9-6 loss to the Yankees. "Fully intend for the front office to make a move. And that's not like something that's a given; it's just that, I know that they want to win and it's a shared interest between the players and the front office.

"I just would assume we'll probably get a pitcher based on the fact that we're not going to run the young guns out for 200 innings. We're going to need somebody to kind of help fill that void. Whether it's Kazmir, Samardzija, Hamels, Cueto, whoever, we're going to expect them to come in and help us out."

Cueto over Hamels?

The Phillies have been using the Astros as negotiating leverage in talks about Hamels, suggesting to others the Astros have heavy interest in the pitcher. But sources say a two- to three-month rental pitcher who will become a free agent this winter, or possibly someone whose contract runs for one more year, is the most likely acquisition for the Astros. In other words, Hamels appears a long shot.

Cueto, sources said, is the most attractive potential acquisition to the Astros at the moment. The Los Angeles Dodgers, Yankees and Toronto also are interested in Reds pitching, a source said.

The Astros had a top scout on hand in Milwaukee recently, and the Reds and Brewers have had eyes on Class AAA Fresno recently.

Before Saturday, it wasn't even clear if Hamels would approve a trade to the Astros. The Astros are one of 20 teams Hamels placed on his no-trade list.

The 31-year-old lefthander on Saturday clarified matters in an interview with CSNPhilly.com, saying he's open-minded to all clubs.

"I had to make a (no-trade) list back in October," Hamels said, per the report. "I came up with a criteria based on a lot of things - winning and losing, family. It was only nine teams. Those teams were in the middle of the pack."

The Astros' winning ways, though, could make him receptive to a deal.

"They just didn't make the nine-team list (of teams I would accept a deal to)," Hamels said of the Astros. "When I made the list in October, who knew?"

The Phillies' handling of negotiations with Hamels has been puzzling to other clubs. "It's like they have their head in the sand," one executive said.

Hamels is signed through 2018, with $96 million guaranteed left on his contract to begin this season. He could demand that for his no-trade clause to be waived, his $20 million team option for 2019 be picked up. (He has a $6 million buyout if the option is not picked up, so the total value of his deal if the option were picked up would be $110 million, including all of this year.)

The 2015-16 free-agent crop is pitching rich, but an argument could be made that Hamels' contract would be more cost effective in terms of salary than signing a top pitcher this winter.

The Reds will listen on Cueto, Leake and even hard-throwing reliever Aroldis Chapman, but Cincinnati's hosting the All-Star Game this year. Shipping players out before the festivities in just over two weeks is highly unlikely.

Luhnow has history with the Brewers' Lohse from their days in St. Louis, but that's not the end-all, be-all. Lohse already has allowed 19 home runs this season - just three fewer than he did all of last season - and the Astros have a proclivity for ground-ball pitchers, McHugh aside. Garza, meanwhile, has a 5.52 ERA, which isn't all that attractive.

The White Sox, who haven't had the type of season they hoped for, are listening on Samardzija, who has a 4.53 ERA.

The Astros like Kazmir and his return to Houston would be a nice story for a kid who went to Cypress Falls, but his second-half ERA last season, 5.42, could be a deterrent - even though he was better in the second half in 2013 when he was with Cleveland (3.38 ERA), than he was in the first half (4.60).

The New York Mets, with a lot of starting pitching, could be a natural fit for a deal with the Astros.

Know thyself

Volume has long been a central part of the Astros' plan. Amass prospects, see which ones pan out and which ones don't.

The problem is that minor league rosters and 40-man rosters can only hold so many players, which is where internal talent evaluation comes in.

How well the Astros judge their own players may be the most important factor this deadline and in their management of the farm system overall. Do they prioritize certain players and do they properly determine which players are better than others? They take the charge seriously and are sending scouts for multiple looks at their farm clubs.

The Astros lost three players in the Rule 5 draft last winter. One of them has been returned to the team, but two likely won't be. Outfielder Delino DeShields Jr. has been a big help to Texas and there's virtually no chance he's coming back.

The Astros could have traded DeShields at some point last year - or found a way to clear roster space for him - but instead lost a former first-round pick for no talent in return.

"You don't know what the chances are that a player is going to make it all year," Luhnow said, referring to the requirement that a player selected in the Rule 5 draft remain on a major league roster all season or be offered back to the team he was taken from. "We obviously would have preferred to have kept Delino. I'll be the first to admit that.

"I didn't think he would be selected and kept all year, and he's stepped up and he's made himself a valuable player that is a useful part of the 25-man roster for a team that's in the race and that's more than I was expecting. Not that I didn't think he was capable of it, but if I were gambling on him doing it or not doing it, obviously, I made my decision."

Roster decisions

The 40-man roster decisions only get tougher from here. But deals present themselves. Baltimore, a source said, has interest in some of the Astros' Class AAA outfielders, L.J. Hoes in particular, as well as Alex Presley. Hoes is on the 40-man roster.

"Yeah, I mean, you could argue that we have a lot of guys to protect, and we're going to leave some unprotected, so why not turn that into something we can use right now? It's a fair argument," Luhnow said. "At the same time, we're looking for the best 25 players, and we never know if that's going to come from those guys that need to be added to the 40-man (roster) down the road or now. You have to balance the short term and the long term.

"We're certainly going to be open to trading players. Whether they're already on the 40-man or have to be added to the 40-man this offseason to ease the logjam a little bit, we wouldn't trade someone just to ease it."

The Astros have a logjam on the big league roster at the corner infield spots with Chris Carter, Jon Singleton, Evan Gattis and Luis Valbuena all on the roster presently and Jed Lowrie to return soon. Valbuena could play first base and Lowrie could play some third.

However that shakes out, the team doesn't believe it needs to resolve the matter this season. By next season, that's a goal. Still, a player like Singleton or Carter could be moved as a chip this deadline.

Jonathan Villar, who still has five tools and this year has shown he can play both infield and outfield, could be a piece in any deal as he sits at Class AAA.

Midseason deals almost always come at an uncomfortable price. But the position the Astros find themselves in, with a team that's mostly healthy in a division that's winnable, is rare.

Not everyone in the Astros organization remains a big fan of Mark Appel. But it would be surprising to see the Astros surrender him for a rental. They have a lot of prospects they really like: Brett Phillips, Michael Feliz, Jandel Gustave, Jacob Nottingham, not to mention some of the young players already in the majors, like Domingo Santana.

The Astros have built the farm system, and quicker than expected, built a competitive major league club. Now, for the first time in his baseball career, Luhnow's job is to give his team the best possible chance to win immediately, and trade the necessary prospects he has compiled to do so.