The big nose tackle was placed on season-ending injured reserve Monday with a torn anterior cruciate ligament in his left knee, a huge loss for one of the league's top-ranked defenses.
"That's hard," Ryan said. "It's going to be hard to replace Kris. There's not many Kris Jenkins playing in this league. Obviously, his impact is going to be felt."
The four-time Pro Bowl selection was injured while making a tackle in the second quarter of the Jets' 16-13 overtime loss to Buffalo on Sunday.
"My feelings are hurt that I won't be able to be out there fighting with my teammates this year," said Jenkins, who was on crutches and had his leg heavily wrapped.
Jenkins, in his second season with New York, said he has "a little bit of a bone bruise on top of it." He added that the medical staff told him it would be a few weeks before the knee is operated on so he can strengthen it and regain his range of motion. Jenkins said part of his hamstring would be used to replace the ACL.
He added he expects to be ready for the start of the team's offseason conditioning programs.
"It still doesn't mean that I won't be around and it still doesn't mean I'm not a part of this team," the 6-foot-4, 360-pound Jenkins said, appearing in good spirits. "I just won't be seen as much, which is fine because I won't have everybody commenting about my weight, so that's OK."
The 30-year-old newly married Jenkins also said he has no plans to retire despite recently saying he has a strong desire to put his family above football.
"I'm not ready to hang the gloves up yet," he said. "I don't think my body is ready to settle down yet."
"There aren't too many 6-5, 360-pounders that can command the respect that he commands," defensive end Marques Douglas said. "He's an excellent defensive lineman, as well as a teammate. He'll be sorely missed."
Jenkins tackled Fred Jackson on a 4-yard run with just over 5 minutes left before halftime and went down as teammate Shaun Ellis rolled into him in the pile. After several minutes on his back, he slowly walked off the field to the sideline before heading to the locker room.
He tore the ACL in his right knee in 2005 while with Carolina, and made the Pro Bowl the following season.
"I'm balanced now," he said with a smile.
Jenkins said he knew something was wrong as soon as he went down.
"I've been through the experience once and you know what that pop is when it happens," he said. "It was a little bit different this time, as compared to the first one because the first time it was just a clean pop, bad position and it went on its own. This time I don't know what happened, but I know I took a blow to it."
He added that he didn't blame Ellis for his injury.
"I know that Shaun plays hard like I do," he said. "Sometimes when you're in the pile, stuff happens. I hope he is not taking it hard. I hope he's relaxed about it because it could have happened to anybody."
The Jets acquired Jenkins from the Panthers in February 2008 for a pair of draft picks, and signed him to a five-year contract worth $35 million, including $20 million in guaranteed money.
He rejuvenated his career after a sometimes tumultuous seven years in Carolina. Jenkins was moved from defensive tackle to nose tackle in former coach Eric Mangini's 3-4 scheme and thrived, making his fourth Pro Bowl. He was performing in a similar role in Ryan's system, and was often dominant -- routinely taking on two blockers -- in the Jets' rushing defense.
"If this was the first time that I would have went through something like this, then it probably would be tough," Jenkins said. "But this is something that I've understood over time. It comes with the game."