Tonkin is dealing with shoulder fatigue and will be unavailable "at least" through the weekend, according to manager Paul Molitor, Mike Berardino of the St. Paul Pioneer Press reports.
It's not clear when Tonkin first started feeling a "dead arm," but he was rocked for nine earned runs over three outings between Aug. 23-26 and has not pitched since. The Twins are hoping a couple more days off will get him healthy again, but he could be sidelined further.