The consensus: More rest is needed, which means Harden most likely won't be returning to the A's rotation for at least two weeks.
"We're going to give his arm a week to 10 days off," manager Bob Geren said before Tuesday's game at Boston.
Harden, who was eligible to come off the disabled list Tuesday, has not thrown in a game since April 15, when he first experienced tightness in his shoulder.
He tried playing catch Thursday but felt soreness and hasn't thrown since.
The A's can go with a four-man rotation for the remainder of this eight-game road trip if they wish. The first game they would absolutely have to have a fifth starter is a May 12 home game against Cleveland.
Left-hander Dallas Braden, who made two starts in place of Harden before being sent down Sunday, is a candidate to rejoin the rotation when that fifth man is called upon.