Chavez, who spent the final two months of the 2007 season on the disabled list and underwent microdiscectomy surgery on his back in early October, received an epidural in the right side of his back during Spring Training. Thursday's targeted his left side, in which spasms forced the A's to shut him down from all activity on March 24 and place him on DL a day later.
"The right side has totally cleared up," said head athletic trainer Steve Sayles, who once again made it clear that there's no timetable for Chavez's return to the field.
"None whatsoever," Sayles said.
Sayles said Chavez, who is fully recovered from offseason surgeries on his left and right shoulders, received the injection in the East Bay and was still in the area. The six-time Gold Glove third baseman is expected to soon return to the Phoenix area, where he makes his offseason home, for treatment.
"He'll go back into rehab and take it from there,"' Sayles said. "The rehab will be two to three weeks. Probably closer to three, to make sure the spasm doesn't return. If the spasm doesn't return, he'll start baseball activities again."
Chavez was said to be at McAfee Coliseum on Friday, but as Sayles predicted, he stayed out of the area to which reporters have access while it was open to the press. Sayles said Chavez's spirits have recently improved.
"His mood, it's all right because he's feeling better," Sayles offered. "I think mentally he's doing good."
If Chavez is cleared for baseball activity in three weeks, it's unlikely he'd be ready to play for the A's until mid- to late May. Former outfielder Mark Kotsay, who underwent a similar back surgery late last spring, needed about a month to get ready to play after he was cleared for baseball activity. He was activated from the DL on June 1.
Mychael Urban is a national writer for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.