New Orleans Saints running back C.J. Spiller underwent arthroscopic knee surgery Friday but is expected to be back for the team's regular-season opener, a source told ESPN's Adam Schefter and Mike Triplett.
Spiller's injury first surfaced a week ago when he missed the Saints' scrimmage. A source said at the time that it was just a day of rest, and Spiller returned to practice in a limited capacity earlier this week. However, Spiller was absent from practice Tuesday and was held out of the preseason opener at Baltimore on Thursday.
It's unclear if Spiller suffered a setback or if he and the team felt a clean-up surgery would be a better choice in the long term. Saints coach Sean Payton didn't comment on Spiller's injury status after practice Saturday.
The Saints signed Spiller to a four-year, $16 million contract in free agency in hopes of adding a big-play dimension that was lacking in 2014 after they traded away runner/receiver Darren Sproles. Spiller, 28, is expected to become a big part of New Orleans' passing attack.
Spiller, who spent his first five seasons with the Buffalo Bills, also missed the last seven games of the 2014 season with a broken collarbone. He doesn't have a history of knee injuries, but he did miss part of one game with a knee issue in 2013. Spiller missed a total of only three games due to injury in his first 4½ seasons before breaking his collarbone.