KANSAS CITY -- Royals general manager Dayton Moore continued his offseason of shaving payroll and restocking his farm system on Monday, as he traded left-hander Ryan Buchter and designated hitter/first baseman Brandon Moss to the A's for right-hander Jesse Hahn and Minor Leaguer Heath Fillmyer.
Moss, who will be making his second stint with Oakland, was owed $8.25 million on the two-year, $12 million deal he signed with the Royals a year ago. The Royals, according to a source, sent $3.25 million to the A's as part of the deal.
The Royals now are without a natural first baseman, which could lead to further speculation they might bring back free-agent first baseman Eric Hosmer. The Royals' payroll now has been slashed to around $107 million with potentially more trades to come to perhaps make room for Hosmer.
"It would be inappropriate for me to comment on a free agent right now," Moore told MLB.com by phone. "[But] I think I've made it clear what our thoughts are about Eric Hosmer."

Hahn, a pre-arbitration player out of options making less than $600,000, likely will get a chance to crack the Royals' rotation, which consists of Danny Duffy, Ian Kennedy, Jason Hammel, Nate Karns and Jakob Junis. Right-hander Trevor Oaks, acquired from the Dodgers in the Scott Alexander trade, also will compete for a rotation spot.
"He's got a great arm," Moore said. "We think there's a lot of value there. He will compete for a spot in the rotation. He gives us more depth there."
Moss hit .207 last year with a .279 on-base percentage. Moss did hit 22 home runs with 50 RBIs, and he was projected to play first base for the Royals this season in the absence of Hosmer.
"Mossy was just a super guy who hit some big home runs for us," Moore said. "He was great in the clubhouse and a super competitor on the field."
Buchter, acquired from San Diego prior to the non-waiver Trade Deadline last July, had a 2.67 ERA in 29 games for the Royals down the stretch.
Hahn, a 6-foot-4, 215-pound 28-year-old, started 13 games for the A's last year and was 3-6 with a 5.30 ERA with a 1.507 WHIP. He struck out 55 hitters in 69 2/3 innings.
Fillmyer, 23, was a fifth-round pick by the A's in 2014. He went 11-5 with a 3.49 ERA in 29 starts for Double-A Midland (Texas) in 2017. He was the A's No. 18 prospect per MLB Pipeline.