Guerra was joined by right-handers Kazuhisa Makita and Colten Brewer and left-hander Brad Wieck in being promoted Tuesday. Over three seasons in the Padres' system, Guerra still hasn't quite pieced it together offensively.
He arrived in the Craig Kimbrel trade prior to the 2016 season as a very highly touted prospect. But Guerra has batted .217 at three different levels since then, and his Minor League strikeout rate has hovered around 33 percent.
Still, there's a noteworthy vacancy at shortstop in San Diego for the start of next season. Freddy Galvis is set to become a free agent and top prospect Fernando Tatis Jr., ranked No. 2 in baseball by MLB Pipeline, is coming off thumb surgery and probably destined to start next year in the Minors.
The Padres have some decisions to make this offseason, and Guerra could factor prominently.
The first question that must be answered is whether to bring back Galvis -- a decision that could hinge on his contract demands and the rest of the league's interest. If the answer is no, the Padres would likely need a stopgap before Tatis' arrival. That's where Guerra could factor in.
In any case, Guerra's glove makes him a roster possibility regardless of how the Padres decide to play it this offseason.
"He's elite defensively at shortstop," said manager Andy Green. "... When you can defend that position, you tend to find some sort of role in the big leagues. For him, that's his primary asset, and his versatility -- we'll test that in time, too."
Guerra is going to get sporadic starts at shortstop -- meaning time on the bench for Galvis, who has started every game there this season. Luis Urias, MLB Pipeline's top-ranked second-base prospect, is likely to start at shortstop, too.
Galvis is the owner of the Majors' longest consecutive games played streak at 309, and Green noted that he'd do everything in his power to get Galvis into those games. But it's clear the Padres have one eye on their future at the position.
At the plate, Guerra hasn't been stupendous this year, but his .774 second-half OPS was a jump of 172 points from the first half. The Padres don't need Guerra to set the world on fire offensively to be a valuable contributor. They'd just like him to hold his own.
"For him, it's just a progression of trusting himself, not thinking too much in the batter's box and cutting loose on the pitches he can hit," Green said. "We'll just try to keep it from being overly complicated."
Guerra struck out in two pinch-hit at-bats in May during a brief callup.
Kennedy's season likely finished An MRI on the left knee of rookie righty Brett Kennedy revealed "serious tendinitis," according to Green, and it appears as though Kennedy's season could be over prematurely.
"We're still trying to work through what the best course of action is for him, but I'd say starting again this year is probably somewhat in jeopardy for him," Green said.
In six starts since his mid-August callup, Kennedy posted a 6.75 ERA. He picked up his first career victory with six shutout frames against the Rockies on Aug. 31. But he struggled in his next start Friday night in Cincinnati. Kennedy allowed four runs in 1 2/3 frames and had trouble with his landing leg -- prompting the Padres to take a look at his ailing left knee.
Worth noting • When Wieck appears in a game, it'll mark the big league debut for the 26-year-old left-hander. He owns a 2.53 ERA in 46 1/3 innings between Double- and Triple-A this season, and he's found a groove lately, too. Wieck has pitched 11 innings since the start of August, and he's allowed just one run on six hits while striking out 22.
"It doesn't matter where I'm at or who I'm throwing against," Wieck said. "It's just about staying focused on what you're doing and your own gameplan and plan of attack."
• Austin Hedges and Francisco Mejia will split time behind the plate over the next three weeks, and the Padres view their trip to Seattle as a chance to get both bats in the lineup. Hedges made his second career start at designated hitter on Tuesday night.
"We're committed here to giving our DH at-bats to our catchers," Green said. "Those two guys right now are very intriguing bats. ... It's no secret we're splitting time back there behind the plate, so the opportunity to get those guys extra at-bats is good."