"It just shows you how fragile this is," manager Mike Matheny said afterward. "That's just one that's going to haunt him a little."
It was a slip that no one saw coming. Weaver had breezed through the Brewers' first eight batters, retiring all -- five via strikeout -- on 30 pitches. Only opposing starter Matt Garza, 1-for-21 this season, stood in the way of wrapping up a clean third inning.
Weaver worked ahead of Garza, 1-2, but followed with three pitches out of the zone. Garza, in his 270th career plate appearance, took his sixth career walk.
"I kind of lost the feel of the ball there," Weaver said. "Sometimes the mechanics get a little out of sync."
It was ill-fated timing, too, as Garza never intended to swing.
"I was just trying to take as many pitches as possible," Garza said. "Keep myself from going back out there really quick. I was telling myself, 'I'd rather you punch out looking than swing at something in the dirt.'"
Two pitches later, Jonathan Villar laced a double. Two pitches after that, Kirk Nieuwenhuis deposited a changeup, the same pitch Weaver had struck him out on earlier, into the right-field stands.
"Every guy, whether it's a young guy or a seasoned veteran, has gone through something like that, where they let a hitter they had a good chance to get out get away," Matheny said. "And the next thing you know, it turns into a big inning. That's exactly what happened. He's going to learn from that."
Weaver showed a capacity to learn quite quickly, which did allow him to finish his night on a high note. He was more measured when he worked into a similar pickle in the sixth. With two runners in scoring position, Weaver refused to give in to cleanup hitter Hernan Perez. He issued the walk, but answered it with an infield popout and strikeout to escape unscathed.
That final punchout was Weaver's 10th of the night, making him one of three pitchers in franchise history with a double-digit strikeout performance in one of his first four appearances.
"I think that was big for me being able to get out of that and being able to keep the score where it was," Weaver said. "Each pitch is super important, because at any moment, they can get some runs off you with just one swing of the bat."