USC Professional Athletes

USC's footprint in MLB got reshuffled at the 2026 trade deadline, and a week into the season's final stretch, both Lars Nootbaar and Marcelo Mayer are defining their post-trade stories in very different ways — one on the field, one in the press.

Nootbaar Settles Into Arizona

The Lars Nootbaar deal is now fully closed. The Cardinals sent the outfielder to the Diamondbacks during the summer for a package that included prospects Daniel Eagen, left-hander Sandro Santana, and a player to be named later. That PTBNL has been revealed as 23-year-old right-hander Brian Curley, a third-round pick in last year's draft, completing the trade and giving St. Louis a full accounting of what they got for their longest-tenured corner outfielder.

Nootbaar, now in left field for Arizona, is doing what he's always done — grinding at-bats and contributing in ways that don't always show up in the box score. He went 1-for-4 with an RBI on September 27 against San Diego, then added a run scored with two walks in the nightcap of what turned into a rough doubleheader for the Diamondbacks (losses of 4-9 and 7-10). His batting average sits at .238, workmanlike but steady for a player who provides real value through on-base skills and defense. Arizona knew what it was getting, and Nootbaar is delivering exactly that.

Mayer's Mouth Is as Loud as His Bat Isn't

Marcelo Mayer's transition from Boston to San Francisco has been bumpier. The Giants acquired the young infielder ahead of the deadline, and Mayer has wasted little time making clear how he felt about his time with the Red Sox — or more precisely, how he feels about them now that he's gone. Per Sports Illustrated, Mayer has taken another public dig at Boston following the summer deal, continuing a pattern of pointed comments that started shortly after the trade.

On the field, the results are a work in progress. Mayer went 1-for-4 on September 27 in a 1-5 Giants loss to the Dodgers, with his average sitting at .209. The raw tools that made him a top prospect are still in there, but the numbers haven't caught up to the narrative yet. The Red Sox, to no one's surprise, have not responded publicly — which may be exactly what's frustrating Mayer most.

There's an interesting tension here: Mayer's vocal frustration with Boston suggests a player who feels he was undervalued or mishandled, the kind of chip-on-the-shoulder energy that can fuel a breakout. Whether that translates into production in San Francisco or just more headlines remains the question hanging over the final week of his debut season as a Giant.

The Bigger Picture

Two USC alumni, two deadline moves, two very different post-trade identities. Nootbaar is the steady professional doing his job quietly in a pennant race. Mayer is the young star still working out his relationship with the sport's spotlight. Both storylines are worth watching as the regular season closes out — and Trojan fans have legitimate rooting interests on both coasts and in the desert.

USC Alumni Week in MLB: Sept. 20–26

Two USC products are sharing a Major League clubhouse for the first time, and a third is making noise in the desert as the regular season winds down.

Mayer and Davidson: Trojan Reunion in San Francisco

The Giants wrapped up a lost season — sitting at 65-93 with just five games to play — but gave USC fans something to track in the final week. San Francisco activated infielder Marcelo Mayer from the 10-day injured list and simultaneously promoted outfield prospect Bo Davidson to the big league roster, with both moves coming during the team's series against the Minnesota Twins. The double call-up was notable enough that Sports Illustrated reported it helped the Giants make MLB history, though the roster transaction alone marks a milestone for Trojan fans: two USC alumni on the same active MLB roster simultaneously.

Mayer's path to San Francisco was turbulent. The former top Red Sox prospect was traded to the Giants for reliever Erik Miller at the deadline — a move both sides apparently welcomed. Mayer and his father were candid about the Boston experience in the days following the trade. "In Boston, if you're going well, you're a god and if you're struggling, they're going to tear you apart," Mayer's father said, per Boston.com. Mayer himself had reportedly wanted out before the deal was finalized, according to Bleacher Report. Now back in his home state, the California native posted a .208–.215 average range across his appearances during the week as he shook off IL rust in series against the Twins and Dodgers.

Davidson, meanwhile, was called up to fill roster spots vacated by injuries to Jung Hoo Lee (groin contusion) and Bryce Eldridge (concussion protocol). With the season effectively over for San Francisco, both USC alumni are getting a look in a low-stakes but meaningful audition heading into the offseason.

Nootbaar Catches Fire for Playoff-Contending Arizona

While the Giants are playing out the string, Lars Nootbaar is doing the opposite — heating up for an Arizona Diamondbacks team with postseason stakes still in play.

The USC outfielder had one of his best stretches of the season over the past week. On Sunday, September 20, he went 2-for-the-game with two runs scored in an 8-4 win over the Yankees. He followed that with a three-hit, two-run effort against Colorado on Thursday. Then on Saturday, Nootbaar went deep — homering and driving in a run while scoring three times and drawing two walks in Arizona's 11-4 blowout of San Diego. His batting average climbed to .241 by the end of the week, solid production for a left fielder playing meaningful September baseball.

The timing couldn't be better. Nootbaar's surge gives Arizona's offense another weapon as the Diamondbacks look to secure positioning heading into October.

Elsewhere

Kyle Hurt logged two innings and two strikeouts for the Dodgers on Wednesday, posting a 4.14 ERA in a low-leverage appearance — though he was subsequently optioned back to Triple-A Oklahoma City when Tarik Skubal returned from the bereavement list. Garrett Stubbs appeared in the Phillies' lineup late in the week as Philadelphia jockeyed toward a postseason berth, slashing just .153 in a backup role.

Lars Nootbaar Hits the Ground Running in the Desert

Lars Nootbaar wasted little time making a statement for his new team. The USC product, acquired by the Arizona Diamondbacks in a trade from the St. Louis Cardinals, delivered his most electric performance of the week on September 15, going 3-for-4 with a home run, two RBI, and two runs scored in a tight 8-7 win over the Miami Marlins. The outing pushed his average to .247 and served as the clearest evidence yet that the change of scenery suits him.

The week wasn't just a one-night flash. Nootbaar also tallied two hits in the Diamondbacks' September 13 game against the Texas Rangers and drew walks in back-to-back Marlins contests on September 16 and 17, showing the patience at the plate that made him an attractive trade target in the first place. By the time Arizona faced the Yankees on September 19, he was entrenched in the leadoff spot in Arizona's lineup — a sign of the trust the organization is already placing in him.

For a Cardinals franchise that parted with Nootbaar in what drew some second-guessing, Sports Illustrated's analysis framed the deal as the right call for St. Louis' rebuild. But for D-backs fans watching Nootbaar slot into left field and immediately produce, the trade looks like a steal from the Arizona side.

Elsewhere in Trojan Nation

It wasn't a banner week for every USC alum in the majors. Garrett Stubbs — the backup catcher for the Philadelphia Phillies — found himself in an uncomfortable spotlight during a blowout loss to the Atlanta Braves on September 17. With Philadelphia's pitching staff exhausted and the game already out of hand, Stubbs was pressed into mound duty by the seventh inning as the Phillies unraveled at Truist Park. It's the kind of cameo no position player wants on his résumé, but it speaks to how badly the night went for Philadelphia as a whole.

Meanwhile, Marcelo Mayer's name surfaced in trade context this week — though not for the Red Sox. The former USC infielder was dealt from Boston to the San Francisco Giants, with Sports Illustrated and Heavy Sports both weighing in on what the move means for the Red Sox. Mayer, still developing his game at the big-league level, heads to San Francisco as Boston prioritized immediate bullpen help in return.

The Bottom Line

Nootbaar is the headliner this week, and rightfully so. His September 15 performance was the kind of multi-tool, high-energy game that defined his best moments in St. Louis — and it came right when Arizona needed a jolt. With the Diamondbacks in the thick of the playoff picture, Trojan fans have every reason to track his at-bats nightly. The rest of USC's MLB contingent had a quieter week, but Nootbaar's showing was enough to carry the banner for the cardinal and gold.