Rooker, 27, is an outfielder who has hit well at every level he’s played, with the notable exception of the big leagues. Drafted by the Twins in 2017, he made it to the bigs in 2020 and got into 65 games as a Twin before heading to the Padres in the deal Chris Paddack–Taylor Rogers trade.
After getting into two games as a Padre this year, he now has 67 MLB games on his ledger, with a tepid .205/.290/.400 line. That production is about 10% below league average, as evidenced by his wRC+ of 90. But he’s always done better at other levels, including this year. In 61 Triple-A games, he’s hit 19 home runs and slashed .272/.385/.605 for a wRC+ of 137.
Despite his lack of success at the big league level, the Royals are clearly willing to be on that minor league track record. Rooker still has options and will finish this season between one and two years of MLB service time, meaning the Royals have time to figure out how to maximize his talents. With Whit Merrifield and Andrew Benintendi having been traded in recent days, Rooker will help shore up some of the outfield depth that has been subtracted.
As for Gallagher, 29, he was a second round pick of the Royals back in 2011 and has been with them since. He made his MLB debut in 2017 and has largely served as backup to Salvador Perez in that time. However, with this year’s promotion of MJ Melendez, it seems he was nudged out of the plans for KC. In 171 career games, he has a slash line of .240/.302/.355, wRC+ of 77. Due to his strong defensive work, he’s produced 1.5 wins above replacement in that time, according to FanGraphs. For the Padres, he figures to serve as depth behind Jorge Alfaro and Austin Nola, with prospect Luis Campusano around as well.