The Rangers have designated lefty Joe Saunders for assignment, tweets Jeff Wilson of the Fort Worth Star-Telegram. Righty Miles Mikolas will be called up to start tomorrow for Texas.

Saunders, 33, owns a 6.13 ERA through 39 2/3 innings after a tough outing last night against the Orioles — the club with whom he last found sustained success. The veteran has struck out just 5.0 batters per nine while maintaining a troubling career-worst 4.54 BB/9. Those peripherals do not leave much room for putting a positive spin on his struggles; Saunders owns a 6.20 FIP, 5.16 xFIP, and 5.21 SIERA.