Wilson was placed on the 15-day disabled list Sunday, two days after he tore the tissue from the knuckle of his left middle finger while hitting a double in the Pirates' loss to Arizona on Friday. He sat out of the team's 3-1 victory Saturday night and returned home Sunday to be evaluated by a hand specialist.
General manager Dave Littlefield said the team would have a better idea of when Wilson can return after the surgery.
"It's hard to say now from a standpoint of time he'll be down," Littlefield said before the Pirates played the Giants on Monday night. "Probably in the vicinity of six to eight weeks before he's game-ready."
If the tissue was not surgically repaired, the tendon could continue to slip in and out of the groove that leads up the finger, Littlefield said.
"It's a very uncommon situation," Littlefield said. "It's a little cloudy what it will look like time-wise."
For now, Littlefield said the Pirates will count on players already in the organization before deciding to add a player from elsewhere.
Wilson was batting .296 with one home run and seven RBI in 26 games and had reached base safely in 13 of his last 19 plate appearances.
He should be able to do cardiovascular exercise and some weight lifting with his legs while the finger recovers.
"With the direction he was headed and what he did last year, we're certainly going to miss his bat in the lineup," Littlefield said. "But this is something that happens over the course of a season. We just have to adjust."