The Giants starting middle linebacker injured his right knee when he collided with an offensive teammate in practice on Monday. Goff still felt pain with the knee on Tuesday and was sent to the Hospital for Special Surgery where he underwent an MRI on Tuesday.
ESPN NFL Insider Adam Schefter first reported the injury.
The team will bring in former Giant linebacker Kawika Mitchell and may sign him shortly, according to a source. They also recently released Phillip Dillard, who worked as the second-team middle linebacker in camp. At the moment, the Giants' second-team middle linebacker is rookie Greg Jones, a sixth-round pick out of Michigan State.
Goff was entering his second season as the full-time starter at middle linebacker and was hoping to take a step forward this year after having 80 tackles last year. He relayed the defensive calls from defensive coordinator Perry Fewell to the huddle.
The Giants have now lost two linebackers in less than a week after Clint Sintim suffered a season-ending knee injury against the Patriots in the preseason finale last Thursday. Their two other starting outside linebackers are Mathias Kiwanuka and Michael Boley.
The Giants' defense has been hit hard by injuries this preseason, having also lost cornerback Terrell Thomas (ACL), Sintim, cornerback Bruce Johnson (Achilles), cornerback Brian Witherspoon (ACL), defensive tackle and second-round pick Marvin Austin (pectoral) for the season.
Defensive end Osi Umenyiora is still recovering from arthroscopic surgery on his knee and could be sidelined for another two weeks or more. And first-round pick, Prince Amukamara, remains out with a broken foot and may not be ready to return until the end of the month or early next month.
Ohm Youngmisuk covers the Giants for ESPNNewYork.com.