"John took me under his wing," Weaver said. "He showed me how to be a big league pitcher."
When Lackey -- lost to the Red Sox for the season following Tommy John surgery -- took free agency to Boston after the 2009 season, he left media and fans to speculate over his replacement as the Halos' ace.
What they'd overlooked was that it already had happened. Weaver, the protégé, was the Angels' best starter in '09, steering them to a third consecutive American League West title.
Weaver is too self-effacing to say it, but he has been the club's staff leader and No. 1 starter ever since. Second to Detroit's Justin Verlander in the 2011 AL Cy Young Award balloting, Weaver, in his prime at 29, stands among the game's elite starters, top five by any reasonable measure.
His stellar work since the '09 breakthrough season hasn't changed Weaver. He'll show his emotions on the field, but he remains humble, thoughtful and understated in civvies, still favoring the look of a surfer dude.
Weaver will never accept credit without first praising teammates, customarily his catcher or the brilliant outfield that runs down the occasional long drive he surrenders.
In Lackey's absence, Weaver frequently hangs out with Dan Haren, the Halos' No. 1A starter. They exchange ideas about their craft, elevating each other in any way possible, along with observations about the world around them.
"I've never been a leader," Weaver said, gearing up for his Opening Day start against the Royals on Friday night, when the Angels take the wraps off Albert Pujols at Angel Stadium. "I've always had guys I looked up to -- and Dan's one of those guys.
"He's very smart in the pitching aspect of the game. We're not going to step on each other, but we talk when we need to. He's got a different arsenal than I have, but we know what each other's trying to do and we'll talk about things. Dan's a good friend -- and a great pitcher."
Since Haren arrived from Arizona in exchange for four players at midseason in 2010, he and Weaver have formed a tandem rivaling any in the game, including Roy Halladay and Cliff Lee in Philadelphia and Tim Lincecum and Matt Cain in San Francisco.
Weaver in 2011 was second to Verlander in the AL in ERA (2.40 to 2.41); third in wins (18); sixth in winning percentage (.692); fifth in opponents batting average (.212); eighth in strikeouts (198); fifth in innings pitched (235 2/3); second in baserunners per nine innings (9.2); second in OPS allowed (.598); and tied with Verlander in quality starts with 28.
Haren led the league in strikeouts-to-walks ratio (5.82); tied for fourth in wins (16); was seventh in OPS allowed (.630); third in innings (238 1/3); third in baserunners per nine innings (9.40); tied for the lead in starts (34); tied with Weaver for fourth in complete games (four); tied for third in shutouts (three); 10th in strikeouts (192); and third in quality starts (26).
"I think what we have most in common is that we're both extremely competitive," Haren said. "We're here to keep our team in games, and we hate to lose. Jered acts laid-back, but he's intense about his job. He works incredibly hard."
Their repertoires vary, but the parallel is in how they have evolved as complete pitchers, their days of throwing in the mid-90s long gone.
Haren employs his cutter more extensively than any other pitch. He also throws a splitter and curve to complement his fastball, which runs in the 89-91-mph range.
Weaver, with a crossover delivery that makes right-handed hitters very uncomfortable, throws a fastball averaging 89 mph more than half the time, hitting corners and moving it up and down. He mixes in curves, sliders and changeups about equally.
Weaver increased his strikeouts from 174 in 2009 to an MLB-high 233 in '10 in part because of the return of an old friend: the soft-serve curve. Long in storage, the hook seemed to come out of nowhere, freezing hitters.
The curveball had been a weapon for Weaver in his final year at Long Beach State. In three years working with pitching coach Troy Buckley, Weaver improved from 8-4 with a 4.37 ERA as a freshman to the 2004 National Player of the Year as a junior. He was 15-1 with a 1.62 ERA, leading the nation with 213 strikeouts as well as wins.
"I threw the curve my junior year, and when I left Long Beach," Weaver said, "Buckley told me it was going to be a great pitch for me as a pro to keep hitters off my fastball. I probably threw it a little too much my first year. I dropped it halfway through my rookie season  and just stopped throwing it, using the slider and change as my offspeed stuff.
"When I came back to [the curve, in 2010], it was because the league was adjusting to me. I started throwing it again and was able to locate it on the outside corner to left-handed hitters. When you're throwing everything as hard as you can, eventually you need a pitch to get somebody out front. The curveball gives me another pitch to keep guys off balance."
Getting outs earlier in counts also has enabled Weaver to work more innings -- from 211 in '09 to 224 1/3 in '10 and 235 2/3 last year.
Weaver won his first six starts in 2011 before enduring a "dead arm" stage in May. He weathered that and didn't miss a start, including the All-Star Game in Phoenix.
A star has arrived full force at the front of manager Mike Scioscia's rotation, but you'll never hear it from Weaver, the Angels' lead dog.
Lyle Spencer is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.