"It's really nothing more than a follow-up to the previous procedure," said Harrison's agent, Bill Parise. "It's nothing new or nothing crazy at all."
The four-time Pro Bowler had his first surgery on Feb. 21 to remove part of a herniated disk in his lower back. But Harrison later announced on his Facebook page that he's getting another surgery Wednesday to clean up the previous procedure.
The original timeline for recovery was about five weeks. But Parise said Wednesday it's now probably closer to six weeks until Harrison will be 100 percent.
"It's just one extra week; that's all we lost there," Parise said of Harrison's rehab. "We don't anticipate any delays in his training or his reporting. James' health will not be an issue at all. He should be good."
Harrison became the second player in Steelers history to record double-digit sacks in three consecutive years. Last season he recorded 100 tackles, 10.5 sacks, two interceptions and six forced fumbles, while helping the Steelers advance to Super Bowl XLV, where they lost to the Green Bay Packers.
James Walker covers the AFC North for ESPN.com.