Kansas City, MO -- (Sports Network) - The Chicago White Sox will place closer Bobby Jenks on the disabled list Wednesday with soreness on the left side of his upper back.

The 27-year old's MRI and CT scan results came back negative over the weekend, but the discomfort has yet to subside.

Jenks has not pitched since June 29 against the crosstown rival Cubs, as he finished off a 5-1 win and a three-game sweep with a scoreless inning of relief. However, the reliever felt soreness near his left scapula the day before and has been dealing with discomfort ever since.

The 6-foot-3, 275-pound closer has converted 18 of 21 save opportunities this season, with a miniscule 1.95 earned run average and a 2-0 record.

Scott Linebrink has been handling the closing duties for the White Sox, but he blew a two-run, extra-inning lead against the Kansas City Royals on Tuesday before the club came back to win, 8-7 in 13 innings.