HOUSTON -- Jeff Luhnow's heart sank when he came across an article prior to the non-waiver Trade Deadline in which Twins right-handed reliever Thomas Pressly was listed as a potential trade chip who could help a contender. Considering the Astros were already in negotiations with the Twins to acquire Pressly, the last thing the Astros president of baseball operations and general manager wanted was more competition.

The Astros restructured the deal and ultimately landed Pressly on July 27, a move that didn't raise many eyebrows at the time. The same was true for the club's trade to acquire Angels catcher Martin Maldonado a day earlier -- a move made to shore up Houston's defense behind the plate.

High-profile trades the Astros made to acquire catcher Brian McCann prior to the 2017 season and pitcher Justin Verlander in August '17 were the final pieces needed to make the ascent to World Series champions last year, but the under-the-radar acquisitions of Pressly and Maldonado have quietly bolstered the Astros' chances of beating the Red Sox in the American League Championship Series. Game 1 is set for Saturday at Fenway Park.

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"Oftentimes, the best deals are not the sexy deals, but the ones that make the most sense for your team," Luhnow said. "They may not be the most household names. Maldonado and Pressly certainly weren't, but those are the two guys we needed, and we targeted them and we went after them and got them, and they've both been an incredible help for us."

Maldonado, who played in 41 games in the regular season for the Astros after appearing in 78 games with the Angels, has perhaps the strongest arm of any catcher in the game, and he should help neutralize a Boston running game that was tied for third in the Majors in the regular season in most stolen base attempts.

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Maldonado led the Majors with a 47.6 percent caught-stealing rate this year, including 62.5 percent (five of eight) with the Astros. By comparison, McCann was at 32.1 percent and Max Stassi -- who wasn't on the AL Division Series roster -- was at 25.6 percent. The Major League average was around 29 percent.

"We wanted to explore getting a catcher who could throw runners out and could really be a weapon for us down the stretch and in the postseason," Luhnow said. "We know that Cleveland runs, we know that Boston runs, we know that other teams are going to try and run, and we've seen historically how shutting down the running game can increase your odds of winning a close game in the postseason."

Especially against the Red Sox. Manager Alex Cora has a tendency to be aggressive on the bases, and Maldonado's ability to throw will be on his mind.

"The cop doesn't always have to pull you over," Astros manager AJ Hinch said. "He just has to be there. You'll slow down."

Maldonado, who will likely catch Verlander in Game 1 and Gerrit Cole in Game 2, said he's always prepared to throw to the bases. Red Sox right fielder Mookie Betts was in the top 10 in the Majors with 30 stolen bases, and Maldonado will have the mindset Betts and all his teammates are looking to run.

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"The day you don't think he's going to run, that's when you're going to be caught by surprise," Maldonado said. "You have to be prepared for them to go every single pitch, even if they don't go."

Pressly, meanwhile, emerged as one of Hinch's best late-inning weapons out of the bullpen, along with closer Roberto Osuna , the former All-Star who came over in a high-profile deal in July. Pressly pitched in 26 games with the Astros and allowed 11 hits and three walk, with 32 strikeouts in 23 1/3 innings. He threw 2 1/3 scoreless, hitless innings against the Indians in the ALDS.

"We've targeted him, we watched him progress," Luhnow said. "He really made some big strides the past couple of years, and I don't know why he was not more of a household name because what he was doing in terms of his arsenal and getting guys to swing and miss. It was pretty impressive."

Since arriving in Houston, Pressly is throwing more curveballs and fewer fastballs, and when he does use the heater, he's going up in the zone more. That works partly because he has elite spin rate on his curveball (3,225 rpm, second-highest in the Majors). As a result, opponents are hitting .158 on fastballs and .057 on his curveballs since joining the Astros. He also has a devasting slider he throws about as much as his curveball.

They may not say it, but Pressly has been even better than they Astros had thought. And they'll lean on him even more against Boston's potent offense.

"You can see the stuff and figure out how much it spins and how much it moves, how fast it is and the trajectory, but you really don't know how effective until you see whether or not batters are able to pick it up," Luhnow said. "He's got one of the top swing-and-miss arsenals in the game. In the postseason, that's huge because any ball put in play could result in something positive for the offense."