The 22-year-old Carrillo, ranked Los Angeles' No. 16 prospect by MLB Pipeline, spent his 2020 at the alternate training site. Last year, he was 5-9 with a 5.44 ERA at Class A Advanced Rancho Cucamonga. The 5-foot-10 righty was signed in 2016 as a free agent out of Mexico.
The 24-year-old Jackson, ranked No. 28 in the organization, also spent 2020 at the alternate training site. Last year, he was 7-2 with a 3.06 ERA while splitting time between Rancho Cucamonga and Class A Great Lakes. He was selected in the 12th round of the 2017 MLB Draft out of the University of Utah despite missing that college season due to Tommy John surgery.
The 22-year-old Uceta, ranked No. 22 in the organization, was a non-roster invite to Spring Training and originally assigned to the alternate training site this year, but he returned home midway through the season. Last year, he was a combined 11-2 with a 2.77 ERA between Rancho Cucamonga and Double-A Tulsa. He was signed for $10,000 as a free agent in 2016 out of the Dominican Republic.
The 27-year-old Reks, not on Los Angeles' Top 30 Prospects list, hit 28 home runs in 2019 while splitting time between Triple-A Oklahoma City and Tulsa. He was a non-roster invite to Major League Spring Training this year and was a 10th-round pick in the 2017 Draft out of the University of Kentucky after transferring from the Air Force Academy.