Nationals' Aaron Barrett: Returning from knee surgery

Barrett underwent right knee surgery this week and has returned to Nationals camp, Jesse Dougherty of The Washington Post reports.

The 33-year-old rejoined Washington on a minor-league deal in November, and he had a knee issue crop up while throwing at the start of camp. Barrett already faced long odds to make the Opening Day roster as a non-roster invitee, and those odds will get even longer as he remains sidelined. It's unclear when the right-hander is expected to return to mound work.