He knew that if he could pound the strike zone early with his fastball, it could end up being a long night for the Red Sox.
Lackey's pregame assumptions proved correct, as he turned in arguably the best postseason start of his career by tossing 7 1/3 scoreless innings to lead the Angels to a crucial 5-0 win in Game 1 of the American League Division Series.
"I don't know if it was the best I've ever been, but I felt pretty good," said Lackey, who won in the postseason for the first time since Game 7 of the 2002 World Series. "In the bullpen, the ball was sinking pretty decent and I had life on my fastball, so I went with that for a while until we had to make some adjustments."
The plan worked to perfection, as Lackey threw first-pitch strikes to the first eight batters of the game and set the tone early.
It was part of an orchestrated game plan devised by pitching coach Mike Butcher and catcher Jeff Mathis to get the Red Sox's hitters behind in the count.
"We just wanted to pound the strike zone, whether it was a fastball or curveball," Butcher said. "We wanted to keep the counts in our favor and stay ahead."
Mathis, like Lackey, could tell from the bullpen session that the fastball would be the pitch of choice as Lackey threw a four-seamer on 16 of his first 18 pitches and 81 out of his 116 pitches, overall.
"He was locating his fastball and keeping it down," Mathis said. "It was a lot of the reason for his success. Any team you can get ahead of hitters, especially this team, it's huge. We tried to establish those first-pitch strikes, and he did a good job with it."
It was also a noticeable to the Red Sox, who saw that Lackey had some of his best stuff reserved for the first game of the postseason.
"He had a lot of life on his fastball," Red Sox manager Terry Francona said. "Looked like he was moving [it] both ways. Threw enough breaking balls we had to respect that, and he was able to locate his fastball again with two different directions."
Lackey also benefited from a three-run homer off the bat of Torii Hunter in the fifth inning to give the Angels a 3-0 lead.
But Lackey said his mindset didn't change after that momentum-shifting swing because he knew the high-powered Red Sox could easily come back.
"You can't relax -- the last thing you can do," Lackey said. "There's too many good hitters in that lineup. But it's nice to know in the back of your mind though, for sure."
Lackey certainly couldn't relax in the next half-inning, as he allowed two runners to reach and had Kevin Youkilis at the plate with two outs.
Youkilis then worked his way to a full-count, but Lackey got him to hit a hard ground ball to third baseman Chone Figgins, who made an athletic play to beat Dustin Pedroia to the bag, ending a potential rally for the Red Sox.
It was just another huge out for Lackey, who seemed to make the big pitches when he needed to.
"I thought he did a tremendous job when he needed that big pitch," said Red Sox leadoff hitter Jacoby Ellsbury, who went 0-for-3. "Guys were battling, and he made that big pitch. He didn't give us too much to hit. Hat's off to him."
Lackey's hat, however, didn't come off until the eighth inning, when he tipped his cap to the sold-out crowd at Angel Stadium after throwing 7 1/3 scoreless innings and exiting with a five-run lead.
It was a fitting gesture for Lackey, who was winless in his previous six postseason starts despite posting a respectable 4.00 ERA in those games.
"Our fans deserved a lot of credit tonight," said Lackey, who allowed just four hits and a walk. "When I came out of the game, that ovation I got was really cool of them. It was a fun atmosphere, that's for sure."
It was also a crucial win at the stadium for the Angels, who snapped a six-game home losing streak in the postseason while also getting their first home playoff win over the Red Sox since Game 4 of the 1986 ALCS.
But Lackey wasn't quite satisfied just yet with just one win over the Red Sox in this year's ALDS.
"It's nice tonight, but our goal is not to win a game," Lackey said. "We want to win the series. We won one game, we've got to get to three before anything really matters here."