Yannick Bolasie will have a knee operation this week in a bid to fix the injury he suffered in the club's final pre-season friendly.
The winger was hurt during the Pilgrims' visit to Saltash United and is unlikely to see any match action until late September.
"He's having an operation on Wednesday," Pilgrims' boss Peter Reid told the Plymouth Herald. "With keyhole surgery nowadays, it won't be a long one, and we're hoping he'll be back in a month or so."
Reid admits he is keen for Bolasie to get back to full fitness as soon as possible.
"It's a blow for us," he continued. "He can stretch people with his pace and his ability to get past defenders, but we've just got to get on with it.
"We've just got to get him back as soon as we can."