The Philadelphia Phillies turned to an outside-the-box solution to upgrade their offense Monday by landing veteran second baseman Luis Arraez in a deadline-day trade with the San Francisco Giants. The deal adds a former batting champion to the lineup but could prompt positional chaos.
The Phillies also received righty reliever Caleb Kilian. They sent pitching prospects Ramon Marquez and Marty Gair to the Giants.
In the wake of acquiring Arraez, who will play second base for the Phillies, they will realign three-fourths of their infield in the middle of the season. It is a rare maneuver that brings questions about how suspect a defensive unit the Phillies can field while still contending for a championship.
They needed a right-handed-hitting outfielder. They instead acquired a lefty-hitting second baseman. It is a creative and fun move at best and a futile stab at inserting square pegs into round holes at worst.
Teams speaking to the Giants about Arraez were aware of his insistence on staying at second base. The Phillies made the trade regardless. He is that meaningful of an upgrade. Arraez, a three-time batting champ, is leading the National League with a .324 average this season. He has an .801 OPS. He has struck out a mere 21 times in 464 plate appearances. Arraez is a contact merchant; he is not like any hitter the Phillies have — or many in the game, period.
Will Luis Arraez trade cause defensive issues in Philadelphia?
Rates and Barrels
Arraez is the focal point, but the Phillies began a modest revamp of their bullpen by securing Kilian and veteran lefty Brooks Raley in a separate trade with the New York Mets. Both deals were agreed upon within minutes Monday morning. The Phillies were not done looking for additions, the league sources said.
But this was the biggest one. Arraez’s addition will prompt Bryce Harper to return to the outfield for the first time since April 2022. Bryson Stott will go from second base to third base, while Alec Bohm will move across the diamond to first base. When asked if he could recall a team making this many midseason position switches during his decades in baseball, Phillies interim manager Don Mattingly said he could not.
The Phillies could have done less rearranging by keeping Harper at first base, moving only Stott to third base and trading Bohm before the deadline. They decided against that.
They also could have asked Arraez to move to first base, a position he has played in the past, while keeping Stott and Bohm in their set spots and bumping Harper to right field. But Arraez was set on playing second base. Another far-fetched scenario, discussed internally, would have kept Harper and Bohm on the infield corners while sending Stott to the outfield.
What they settled upon is a fascinating way to address the lackluster lineup. The Phillies were already one of the worst, if not the worst, defensive clubs in baseball. They are leaning into so much uncertainty with this trade.
Arraez, 29, entered this season as a .317 lifetime hitter and he’s contending for what would be his fourth batting title while playing in an era of hit suppression and plummeting averages. There’s no doubt he’s an outlier in today’s game. Yet it’s more difficult to determine the true value of his offensive skills, which is why the Giants were able to sign him to a modest one-year, $12 million contract.
It was the Giants’ best move in an otherwise unsuccessful winter. Arraez has been a shining light in a dismal season and he’s rebuilt his defensive reputation at second base while ranking near the top of the list for all defenders in Outs Above Average and Fielding Run Value. He became an instant fan favorite in San Francisco with his feisty and competitive at-bats.
As an impending free agent, though, there wasn’t much doubt that the Giants would seek to move Arraez before the trade deadline. His elite bat-to-ball skills figured to be in high demand among contending clubs, especially after teams such as the Toronto Blue Jays and Milwaukee Brewers used high-contact lineups to churn through postseason opponents last October.
Arraez has the slowest average bat speed in the league, but that’s by design. His ultra-short swing allows him to wait till the last instant to make a swing decision, and then he keeps his bat in the zone for as long as it takes to make contact. He won’t draw walks, and nobody in the game is more geared to swing with two strikes — amazingly, he had just two called strikeouts in 675 plate appearances last season. He’s the rare hitter who lacks power but is otherwise someone you’d want at the plate in an RBI situation.
Kilian, 29, is an enticing bullpen addition for the Phillies. He had eight career games in the majors before this season and spent an injury-riddled 2025 in the minors. But he is throwing harder than ever, averaging 97 mph with a fastball that has held opponents to a .296 slugging percentage. He has a 27 percent strikeout rate with a few too many walks, but he fits in the middle of the Phillies’ bullpen. He also has five years of club control remaining.
The Phillies paid a price in Marquez, who quickly established himself as one of the best pitchers in their system this season. He highlights the return for the Giants.
The 20-year-old righty was widely viewed as one of the Phillies’ best pitching prospects. He has a strong changeup and his fastball velocity has improved since he came stateside last year. His ability to develop a strong breaking pitch remains a question mark; he throws a slider, but it’s his weakest pitch. Nonetheless, he has made a name for himself in just a year and a half since signing for $10,000 out of Mexico.
Gair, a 23-year-old righty reliever, was recently promoted to the Phillies’ High-A affiliate. He has posted a 4.50 ERA across 36 innings this season. Injuries have derailed much of his development, as he has only pitched 63 innings since being selected in the 13th round of the 2023 MLB Draft. But his fastball averaged nearly 98 mph in the Low-A Florida State League this year, where he struck out more than 40 percent of the batters he faced.
