Kampman was ruled out for the season after tearing a knee ligament Thursday, leaving Jacksonville without its best pass rusher and a locker-room leader.
Kampman tore the anterior cruciate ligament in his right knee during a non-contact drill. Tests Friday revealed the severity the injury, and Kampman is set for surgery at a later date.
The Jaguars (4-4) signed Kampman to a four-year, $26 million contract in March to upgrade a defense that had a league-worst 14 sacks in 2009.
The 6-foot-2, 296-pound Collins spent the first nine weeks of the season on the Giants' practice squad after signing with them as an undrafted rookie.
The Associated Press contributed to this report.