KANSAS CITY, Mo. -- When he was traded to the Kansas City Chiefs last offseason, quarterback Alex Smith professed his admiration for coach Andy Reid and his excitement at playing for the storied franchise.
Now, he could have that opportunity for at least four more years.
Smith signed a $68 million extension Sunday to remain with the Chiefs through the 2018 season, a person familiar with the deal told The Associated Press. The person spoke on condition of anonymity because the team did not disclose the terms of the contract.
Smith, who is due $7.5 million this season, will receive $45 million in new guarantees.
"It was a priority of ours to get this deal done and keep Alex in a Chiefs uniform long term," Chiefs general manager John Dorsey said in a statement. "Alex is a proven leader on and off the field. He is a special individual with a lot of ability and we are fortunate to have him here."
Smith and his agent, Tom Condon, had been discussing an extension for several months, and both sides were hopeful that a deal would be reached by the regular season. But with the Chiefs opening against Tennessee next weekend, time was quickly running out.
"John and his staff along with Tom and his group have worked hard to get this deal done. They've done a nice job," Reid said in a statement. "Alex is a smart, talented football player that has adapted well to our offensive scheme. He also, obviously, has had a tremendous amount of success as a quarterback in this league. We as a team are very happy to have Alex as our quarterback."
The Kansas City Star first reported that Smith had reached an agreement.
The former No. 1 overall draft pick joins a wave of quarterbacks who have recently signed long-term extensions, including the Bengals' Andy Dalton and the 49ers' Colin Kaepernick.
Smith has not played well in the preseason, throwing two interceptions in the red zone in his final outing against Minnesota. But he's been hampered by an offensive line in turmoil, an injury to running back Jamaal Charles that kept him out two weeks of training camp, and a suspect group of wide receivers that will start the season without suspended star Dwayne Bowe.
"I feel good. I mean, I feel great," Smith said last week. "We got some good work, some things to learn from to get better, but I do -- I do feel confident in what we're doing."
Smith's deal is important for the Chiefs on other fronts, too.
Now that he's under contract, they can turn their attention toward a long-term deal with Pro Bowl pass rusher Justin Houston. And if they fail to reach an agreement with him, the Chiefs could put the franchise tag on Houston without worrying about losing Smith to free agency.
After arriving in Kansas City for a pair of second-round draft picks, Smith had possibly the best season of his career. He threw for a career-high 3,313 yards and 23 touchdowns against only seven interceptions, even while skipping a meaningless regular-season finale.
More importantly, he took a downtrodden team that had won two games before his arrival to an 11-5 record and the playoffs. Smith threw for 378 yards and four touchdowns in a 45-44 loss to the Colts, setting playoff franchise record with 30 completions and 46 attempts.
Smith's won-loss record the past three seasons is 30-9-1, trailing only the Patriots' Tom Brady, Packers' Aaron Rodgers and Saints' Drew Brees in wins among QBs with at least 30 starts.
Now with a year in Reid's system, Smith thinks he can be even better this season.
"It's always a progression. It's not like we've arrived anywhere," he said recently. "I mean, last year is a great example of where we started the season and where we ended it. Every season is like that.
"There are ups and downs along the way throughout the season, but you've got to continue to progress. You want to be playing your best football as the season goes on and into late in the year. So, you're never just at a place. You're always striving to be moving forward."
Now, Smith knows that he'll be moving forward with Kansas City.
AP Sports Writer Janie McCauley in San Francisco contributed to this report.