Arizona traded Alek Thomas to Los Angeles, which confirmed a DFA for Michael Siani to free a roster spot.
A roster shuffle is taking shape in Los Angeles, with the Dodgers completing a trade that sends Diamondbacks center fielder Alek Thomas to the team while triggering a corresponding move for Michael Siani.
The teams have officially announced the deal. with Los Angeles confirming the decision to designate Siani for assignment as part of the transaction workflow.. The trade also involves a player returning to Arizona: minor league outfielder Jose Requena. according to the transaction information that first appeared on the MiLB.com tracker and was later confirmed by Francys Romero.
The timing traces back to last week. when Arizona designated Thomas for assignment after calling up top outfield prospect Ryan Waldschmidt.. In the broader context. Arizona had already been weighing possible trade scenarios involving both Thomas and Jake McCarthy for several seasons.. McCarthy, in particular, is now already off the Diamondbacks roster after being shipped to Colorado over the offseason.
For Los Angeles, the practical side of the trade centers on roster space.. The Dodgers have a full 40-man roster. and while the team did not immediately announce the corresponding move until the trade was finalized. its MLB.com transaction log showed that Siani was designated for assignment the previous night.. That step is expected to create the room required to bring Thomas into the organization while keeping the roster structure intact.
The swap also clarifies what the Dodgers are trying to solve.. Thomas is coming in as left-handed hitting depth in the outfield, effectively filling a spot for a center-field capable option.. That matters because the Dodgers have been operating without a true backup center fielder behind Andy Pages. while limitations on roster flexibility constrain who can be moved through options.
Thomas’s profile is a familiar one for teams looking for upside on defense.. The 26-year-old was a former second-round pick and once stood out as one of MLB’s better prospects when he debuted in 2022.. Across the minor leagues. he was well regarded for his defense. and it also showed up in how he developed at every stop.. But at the major-league level. his offensive production has lagged behind expectations. with results over his four-plus seasons showing a well-below-average hitter.
This season’s approach has highlighted both the strengths and the trade-off in Thomas’s offensive game.. He is an extremely aggressive hitter. ranking in the top 15 this year in both overall swing rate and chases off the plate.. His hitting has been particularly difficult against off-speed pitches, and consistently low walk rates have held down his on-base percentage.
Over time, the numbers have reflected that reality. Thomas has a career batting line of .230/.273/.361 across just shy of 1,500 plate appearances, and it corresponds to the ninth-lowest OBP among hitters with at least 1,000 trips since the start of 2022.
Even so, the defensive value remains the centerpiece.. Thomas has built a strong reputation with the glove, earning rates as an above-average defender and baserunner.. His sprint speed and defensive grades have dipped slightly after he suffered a left hamstring strain early in 2024. but he still projects as a reliable option in center-field responsibilities.
Arizona’s decision-making has also been tied to how its outfield is currently set.. Between Corbin Carroll and Lourdes Gurriel Jr.. center field is being manned by Waldschmidt and Jorge Barrosa. with Waldschmidt earning his way into the major-league picture after being called up—part of the reason Thomas’s roster status changed.. With Thomas moved out and the organization reshaping its outfield mix. Arizona’s next phase includes integrating Waldschmidt and Barrosa into the broader lineup.
The transaction also affects what happens immediately in the minors.. Thomas still has a minor league option remaining. so he is expected to begin his time with Los Angeles in Triple-A.. That fits a typical pattern for teams adding outfield depth while preserving roster flexibility and awaiting the right opportunity for a call-up.
Los Angeles’s roster constraints also explain why the trade is described as a “buy-low” move.. The Dodgers cannot option Santiago Espinal or Miguel Rojas, which narrows how they can adjust without exposing players.. Meanwhile. Alex Call is noted as a better fit for a corner role and has options available. and he has been producing as a right-handed platoon player.. In addition. the Dodgers are expected to get Kiké Hernández back from the injured list about two weeks from now. which can further influence how outfield responsibilities are distributed.
Money is part of the equation, even if it is not expected to dominate Los Angeles’s planning.. The Dodgers will assume roughly $1.4MM of the remaining salary on Thomas’s arbitration figure of $1.9625MM. with the report indicating the specific obligations.. The transaction also brings additional costs: Los Angeles will pay just over $1.5MM in luxury tax commitments.
From an organizational strategy standpoint. those commitments are described as manageable. with Los Angeles having the ability to retain Thomas via arbitration for at least two more seasons.. There are also service-time details that matter for long-term planning—Thomas would need to accrue another 20 days on the MLB roster in 2026 to surpass four years of service time. keeping him on track for free agency after the 2028 campaign.
If Thomas instead spends at least 20 days in the minors, he would be out of options next year.. That distinction is important for both sides. because it affects how the Dodgers can move him between levels and how Arizona’s former center-fielder role ultimately gets defined once he settles into the organization.
Meanwhile. the wider trade logic underscores a common theme in MLB deal-making: defense can be a path to value even when the bat has not fully caught up.. Thomas’s reputation as an above-average center fielder and baserunner is the kind of asset teams can plug into late-season depth plans. especially when roster mechanics and injuries force managers to think several moves ahead.
For Arizona, the trade also reflects a shift toward new looks in the outfield.. With Thomas already designated for assignment last week and Waldschmidt and Barrosa now handling center-field duties between Carroll and Gurriel Jr.. the Diamondbacks have moved on from an earlier evaluation that included lingering trade discussions involving both Thomas and McCarthy.
More to come.
Alek Thomas trade Dodgers roster move Michael Siani DFA Diamondbacks outfield Ryan Waldschmidt call-up MLB transactions