(CBS) The Cubs have added more pitching depth to the organization, acquiring right-hander Alec Mills from the Royals in exchange for minor league outfielder Donnie Dewees on Wednesday evening.

The 25-year-old Mills posted a 3.22 ERA in 125 2/3 innings split between Double-A and Triple-A in the Royals organization last season. He was 4-3 with a 4.19 ERA in 12 appearances, 11 starts, with the Triple-A Omaha club. Mills made his major league debut in May, then again joined the team in September and surrendered five earned runs in 3 1/3 innings.

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Mills was designated by assignment for the Royals to make room on their 40-man roster for newly signed right-hander Jason Hammel, who has pitched for the Cubs the last two seasons.

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Dewees, 23, hit .278 with 10 home runs and 103 RBIs in 195 games in the minor leagues since arriving in the Cubs organization as a second-round pick in 2015.

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Left-hander David Rollins was designated for assignment to make room for Mills on the Cubs’ 40-man roster.