By Bruce Levine–

CHICAGO (CBS) — The waiting has been tough for White Sox right-hander James Shields, who’s currently on the disabled list for the first time in his 12-year big league career.

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After getting off to a solid start, the 35-year-old Shields went placed on the DL in April with a strained right late. Since that time, he has only worked on conditioning.

On Monday, Shields will attempt to throw on flat ground for the first time since incurring the shoulder soreness.

“They wanted to give this 12 to 15 days of rest and let it heal on its own,” Shields said Sunday. “There is nothing really to do but wait. I will throw tomorrow in Anaheim and see how it goes.”

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There remains no timeline for Shields’ return.

“I feel great,” he said. “It sounds weird, but the only time it hurts is when I throw. Right now, I have done everything I possibly can. I have got this thing as strong as I can get it. We’ll see how it goes.”

Shields is 1-0 with a 1.62 ERA in three starts. That was a welcome sight after a nightmare 2016 campaign in which he was 6-19 with a 5.85 ERA. The White Sox owe Shields $20 million across the 2017 and 2018 seasons, with the Padres picking up the rest of his money. He has a team option for 2019.

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Bruce Levine covers the Cubs and White Sox for 670 The Score and CBSChicago.com. Follow him on Twitter @MLBBruceLevine.