Could Elvis Dumervil, the league's leader in sacks last season, be next?
Dumervil is in the same situation as Kuper. Both were drafted in 2006. Both entered this season as restricted free agents. Both were searching for financial stability.
Kuper's deal is worth $29 million with nearly $13 million in guarantees, sources told ESPN.com's Bill Williamson.
The agreement came as a pleasant surprise to Kuper, especially since there's no salary cap in 2010.
"I'm very, very happy that it did happen," Kuper said Friday in a teleconference call. "I think there's guys out there that were getting deals done. Not a ton, but to be one of those guys, it's an unbelievable feeling."
While all the attention was focused on whether Dumervil would receive a new deal, Kuper's negotiations slipped under the radar. Kuper signed his tender of $2.521 million this spring, as did quarterback Kyle Orton ($2.621 million), who's still waiting to hear word of a long-term commitment.
Dumervil recently signed a waiver to participate in passing camp, but not his tender worth $3.168 million.
"There were a lot of question marks with this offseason, with this uncapped year and what was going to happen with the restricted guys," Kuper said. "Were guys going to be signed to long-term deals?"
"I haven't talked to Elvis too much about it. It's his personal deal, too," said Kuper, a standout at the University of North Dakota. "I'll let him take care of his end of it."
The 6-foot-4, 303-pound Kuper started 15 games for the Broncos last season after missing the season opener with an ankle injury.
According to STATS Inc., Kuper has allowed just five sacks in 42 career starts.
Broncos coach Josh McDaniels said in a release Friday that the Broncos look forward to his "leadership and toughness in our efforts to build a championship caliber team."
Denver started off strong last season under McDaniels, jumping out to a 6-0 start. But the team faltered down the stretch and missed the playoffs with an 8-8 record.
Still, Kuper thinks the Broncos are headed in the right direction.
"We're going to have a lot of success in the near future," he said.
Kuper has proven to be quite adaptable on the offensive line. He came in learning Mike Shanahan's zone-blocking scheme. But when McDaniels took over for Shanahan, Kuper had to adjust to more of a power system.
"We ran some power stuff in the past. We didn't major in it," Kuper explained. "I feel like I can play in any system."
Clady is recovering from a partially torn left patellar tendon, the result of an injury while playing basketball. Harris was hampered by toe problems last season, before being placed on the injured reserve in December. He returned to the field Friday for passing camp.
"Those two guys are, in my opinion, two of the best at their positions in the league," Kuper said. "To be able to play next to Ryan Harris all the time makes me a better player. Ryan Clady came into this league and played awesome. To have us three guys playing together, hopefully for a long time, we're going to do some good things up front."
ESPN.com's Bill Williamson and The Associated Press contributed to this report.