The third baseman said on Tuesday that much of the pain had subsided, and he has much better movement than when he first suffered the injury Saturday in Chicago.
"I think that had a lot to do with the swelling the last couple days," Wigginton said. "Every day is getting better, and I think that's a positive."
Wigginton's immediate future will be determined Thursday, when he tests his left thumb during a short workout at Minute Maid Park. He'll spend the off-day taking practice swings and playing catch, and if the session doesn't go well, he'll probably be placed on the disabled list.
So far, the club has resisted putting Wigginton on the DL with hopes the third baseman can heal quickly enough to return to game action by Friday.
"His big day will be Thursday," general manager Ed Wade said. "We'll want to give him enough time to see if this resolves itself, so to speak. It's not going to resolve itself from the standpoint that a fracture is a fracture, but if he can show us on Thursday that he can grip a bat and catch the ball, then it probably behooves us to keep him active.
"If not, at that point, it's in all fairness to [manager Cecil Cooper] to have a full assortment of players. We'll probably have to make a move and put him on the disabled list."
Wigginton appreciates Wade's willingness to give him time to prove he's healthy enough to avoid the DL.
"I'm going to be 100 percent honest with them," he said.
Alyson Footer is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.