Marco Estrada: Cut loose by Oakland

Estrada (back) was released by the Athletics on Tuesday, Martin Gallegos of MLB.com reports.

Estrada was on the 60-day injured list due to a back strain, and after struggling through his last three rehab outings, he's been issued his release. The veteran right-hander accrued an unimpressive 6.85 ERA and 1.31 WHIP with 11 strikeouts over five starts with Oakland this season (23.2 innings), and he hasn't pitched in the big leagues since April 16.