NEW YORK -- Boston Red Sox lefty reliever Robbie Ross Jr. underwent microdiscectomy (lumbar spine) Wednesday.

Dr. Louis Jenis performed the surgery at the Newton Wellesley Spine Center.

He's expected to be ready for spring training 2018, per the Red Sox.

Ross has been on the disabled list since June 1 with left elbow inflammation. He also spent time on the DL earlier this year with influenza.

He appeared in just eight games for Boston and allowed seven runs, 12 hits and five walks while striking out nine over 9 innings. He also hit three batters.

Ross was a valuable reliever for Boston both in 2015 and 2016.

He's eligible for free agency following this season.