BOSTON -- The Rangers designated left-hander Dallas Keuchel for assignment before Sunday's series finale against the Red Sox.

The 34-year-old Keuchel was 0-2 with a 12.60 ERA in two starts for the Rangers, including taking the loss Friday when he allowed seven runs in 4 2/3 innings. He is 2-9 with a 9.20 ERA in 14 combined starts with the Chicago White Sox, Arizona Diamondbacks and Rangers this season.

"I felt I pitched a whole lot better than the line read," Keuchel said after Friday's game. "It felt like I was making pitches and they were battling like the classic Red Sox game at Fenway Park. I established all my pitches, but this year is what it is. We're working toward an end goal of putting up some zeroes."

Keuchel, the 2015 American League Cy Young Award winner, joined the Rangers as a free agent July 26.

They recalled left-hander John King from Triple-A Round Rock to take his spot on the roster. King pitched three scoreless relief innings during the Rangers' 5-2 loss.