At that point, he was just concerned about making the Dodgers' postseason roster, just concerned about being brought along for the ride.
The thought that he was going to play a pivotal role in giving his club a 5-3 win in Game 1?
But that's exactly what happened when Randy Wolf struggled in his first career postseason start, and Weaver was brought in to face Ryan Ludwick with two outs and the bases loaded in the top of the fourth with the Dodgers up, 3-2.
The man who made only five appearances in the final month of the season controlled the fate of the Dodgers' playoff hopes.
And he delivered.
On the immediate pitch after Ludwick missed a multi-run blooper down the left-field line by a couple of inches, Weaver threw another slider and induced a harmless grounder to end the inning.
The veteran right-hander came out to pitch a scoreless fifth to earn an improbable win -- against the same club he won a World Series title with in 2006.
"It's a game of inches, huh?" Weaver said. "Luckily it curled enough to go foul.
" ... My last few postseasons have been against old teams, with Detroit in the Series and now St. Louis."
Even if it was aided by good fortune, there weren't many moments during Wednesday's game that carried more potential impact.
DODGERS' BULLPEN IN GAME 1
|Jeff Weaver*||1 1/3||1||0||1|
|Jonathan Broxton**||1 1/3||2||1||2|
Give up a hit, and the Cardinals retake the momentum and possibly roll to a big inning. Escape, and the Dodgers deal their own blow to the Cardinals' morale.
"There probably wasn't a bigger out to get than Weaver's when he got Ludwick," Dodgers manager Joe Torre said.
That's no hyperbole. The Dodgers tacked on insurance runs in the bottom of the fifth and sixth, and the Cardinals never again had a potential winning run at the plate.
The postseason is full of unlikely heroes, and now Weaver's name can be added to the list.
He went from finding out toward the end of Tuesday's workout that he won the final postseason roster spot over fellow reliever James McDonald to entering the game in a bases-loaded situation.
Talk about the emotional ebb and flow that goes with being a baseball player.
"That's exactly what it is," Weaver said. "Everything you can control you try to, and if you can't, you deal with it. I was lucky to get in there early and do well and that's what I expect to do."
Ask some other guys on the club about Weaver's performance and there's no hint of surprise in their answers or any references to luck.
"He's been good for us all year," said lefty reliever George Sherrill, who recorded two outs in the eighth. "He's come in there and picked up some innings for us when we need it, and just looking at his numbers, he's done a really good job for us."
Weaver appeared in 28 games for the Dodgers this season in outings ranging from spot starts, long-relief appearances and single-inning stints out of the bullpen.
Maybe that's why Weaver didn't admit to the notion that what transpired Thursday could have been unthinkable a day ago.
"I expect any scenario," he said. "You have to be ready for anything that goes down because you never know how a game's going to play out.
"I'm ready from the first inning on."
David Ely is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.