Kirkpatrick is not expected to undergo surgery.
Kirkpatrick was expected to challenge for one of the starting cornerback spots, especially with the uncertain status of Leon Hall (Achilles injury). Now, Kirkpatrick could miss the start of the regular season.
Kirkpatrick, the 17th overall pick in the NFL draft, reportedly was hurt preparing for camp. The Bengals could place him on the non-football injury list and not pay him for the time he is out.
Kirkpatrick confirmed his injury Tuesday night on Twitter, saying, "I'm sorry about my injury and im going to try my best to get back and help the team to get to a Super Bowl and once again I'm sorry."
Information from ESPN.com's Jamison Hensley was used in this report.