Royals acquire pitcher Luke Weaver from Arizona for Emmanuel Rivera

The Royals have acquired pitcher Luke Weaver from the Arizona Diamondbacks for third baseman Emmanuel Rivera, according to John Gambadoro of 98.7 FM in Phoenix and confirmed by several sources.

Weaver is a 28-year-old right-hander who has been plagued with right elbow inflammation this season. He has pitched in just 12 games, mostly in relief, with a 7.71 ERA, but a 2.69 FIP and 19 strikeouts in 16 1/3 innings. He has been a starter for most of his seven seasons in the big leagues with 81 career starts and an overall ERA of 4.76. He has battled injuries much of his career, and has only made over 20 starts in a season once, in 2018. He had a a forearm strain in 2019 that limited him to 12 starts and a right shoulder strain in 2021 that limited him to 13 starts.

Weaver was originally a first-round pick by the Cardinals in 2014 out of Florida State. Baseball America ranked him as the #50 prospect in baseball before the 2017 season and he had a 3.88 ERA in 60 1/3 innings for the Cardinals that year. The next year he pitched in a career-high 136 ¹⁄₃ innings with a 4.95 ERA and was part of a package of three players traded to Arizona for All-Star first baseman Paul Goldschmidt.

Weaver throws a fastball that sits at 93-94 mph with a cutter and a change up. Ben Clemens at Fangraphs wrote that Weaver could be a good candidate for improvement in the right hands.

I’ve written a lot of words about my enduring pitcher crush, but I think it basically boils down to this: if Weaver can combine his new fastball shape with changeup command, I’m into it. His changeup has, at times, been an excellent secondary pitch even against right-handers. Even in 2021, when the pitch got tattooed overall, he got swinging strikes on 17.5% of his right-on-right changeups. That plus the cutter against righties, and a fastball/changeup diet to lefties, should make for a solid major league starter.

Weaver is arbitration-eligible for the second time this year and is earning $2.875 million. He has one more year of club control before he is eligible for free agency after the 2023 season.

Emmanuel Rivera appeared in 92 games over the past two seasons with the Royals and hit .243/.294/.378 with seven home runs. He was originally a 19th-round pick in 2015 out of Puerto Rico, but the power he showed in Triple-A never translated to the big leagues, and his defense showed flashes but was inconsistent.

The trade is a bit of a head-scratcher in that Weaver is not a cheap player, but he has not been particularly good. The loss of Rivera shouldn’t hurt too much as he seemed like a replacement-level player. The Royals could certainly use some more pitching depth, and it will be interesting to see if they have Weaver start as he has in the past or if he continues to pitch out of the pen.