Cubs acquire pitching depth in trade for K.C. righty Alec Mills

The Cubs’ search for rotation depth continued Wednesday, when they acquired the right-hander the Royals cut loose to make room for ex-Cub Jason Hammel.

Right-hander Alec Mills, a minor-league starter who debuted with three relief appearances last season, was acquired for minor-league outfielder Donnie Dewees.

To make room on the 40-man roster, the Cubs designated recently acquired David Rollins for assignment.

The Cubs return all four starters from their World Series roster but have little reliable rotation depth beyond that.

In the last two weeks, they also acquired left-hander Brett Anderson and traded for right-hander -Eddie Butler.

Anderson will battle lefty Mike Montgomery for the fifth-starter job in spring training. Butler and Mills likely will join the rotation at Class AAA Iowa, along with lefty Rob Zastryzny and Aaron Brooks.

Hammel, who was dropped from the playoff rotation, became a free agent when the Cubs declined his $12 million option for 2017. He signed a two-year, $16 million deal with the Royals this week.

Mills, 25, is a former 22nd-round draft pick from Tennessee-Martin. He allowed five runs in 3⅓ innings with five walks and four strikeouts for the Royals last season. He was 4-3 with a 4.19 ERA in 12 games (11 starts) for Class AAA Omaha last season.

Dewees, 23, was the Cubs’ second-round draft pick in 2015. The left-handed hitter batted .278 with 10 homers and 50 stolen bases in 195 career minor-league games, reaching advanced-A Myrtle Beach last season.