KANSAS CITY, Mo. (AP) — The Chicago White Sox promoted second baseman Nick Madrigal on Friday, adding one of their top prospects to the roster.The 23-year-old Madrigal had been training at the team's auxiliary site in Schaumburg, Illinois. Veteran reliever Kelvin Herrera was designated for assignment.Madrigal was in the starting lineup for the opener of a three-game series at Kansas City, batting ninth in his big league debut.“It’s been a long time coming. I’ve imagined this moment for a long time, since I was a little kid,” he said. "It’s a little different with the stadium empty, but it’s still a dream come true. It’s something I’ve worked extremely hard for for a long time.”Madrigal was selected by Chicago with the fourth overall pick in the 2018 draft after a standout collegiate career at Oregon State. He is wearing uniform No. 1.The 5-foot-8 Madrigal hit .311 with four homers and 55 RBIs in 120 games over three minor league stops last season, finishing the year at Triple-A Charlotte. Known for his bat-to-ball skills, he had 44 walks and 16 strikeouts in the minors in 2019.He was with the team during its summer training camp, but didn't make the opening-day roster.“I was disappointed. I wanted to help this team win from the beginning; that was one of my goals. It didn’t work out," he said. "When I went to Schaumburg I wasn’t down at all. I was a little mad. It’s not my style to pout and be angry for more than a couple of days. I tried to stay focused. I feel good at this point.”Herrera signed an $18 million, two-year deal with the White Sox in January 2019. He had a 6.14 ERA in 57 appearances in his first year with the team. He was charged with four runs in two innings in Chicago's 14-2 loss to Minnesota on Sunday.___More AP MLB: https://apnews.com/MLB and https://twitter.com/AP_Sports