Although Lamar Jackson and the Baltimore Ravens have kept details of their contract negotiations private, the star quarterback turned down a five-year extension offer worth over $250 million with $133 million guaranteed at signing, sources told ESPN.

The extension, which ran through the 2027 season, would have increased the total value of Jackson's deal to just under $274 million over six years, according to sources. Jackson would have played out the $23 million fifth-year option on his rookie deal before the extension started in 2023.

The extension years in the Ravens' proposal would have paid Jackson a higher average salary than the deals signed this summer by Broncos quarterback Russell Wilson and Cardinals quarterback Kyler Murray and also included more money guaranteed at signing, according to sources.

But sources told ESPN that the Ravens also balked at Jackson's wish for a deal that was fully guaranteed at signing, similar to Deshaun Watson's, prompting the sides to announce Friday that they had tabled contract talks until after the 2022 season.

Wilson signed a $242.5 million deal earlier this month that averaged $48.5 million annually and included $161 million guaranteed, about six weeks after Murray received a $230.5 million deal that averaged $46 million per year and included $189.5 million guaranteed.

But the issue for Jackson wasn't Wilson's deal or Murray's so much as it was Watson's, according to sources. The Browns signed Watson to a $230 million contract that was fully guaranteed at signing. The Ravens' offer of $133 million fully guaranteed at signing was more than both Wilson's ($124 million) and Murray's ($103.3 million) but well short of Watson's.

Jackson acted as his own agent in the negotiations while leaning on the help of his mother and the NFL Players Association, whose job it is to offer stats, information and guidance and to be a sounding board during the process.

The union advised Jackson, 25, that based on his performance and age, he was justified to demand a fully guaranteed contract, sources said.

Union sources framed the Ravens' talks with Jackson as "good faith," although the team included $2.5 million in annual deescalator clauses if Jackson did not attend a high percentage of offseason workouts.

Jackson will make $23.016 million in his fifth-year option but has no guaranteed money after this season. He hopes to land an extension after this season with the Ravens, who are expected to apply their franchise tag on Jackson and prevent him from hitting free agency if the sides still are unable to reach a deal.

Jackson is making the biggest bet in football on himself, similar to what former Ravens quarterback Joe Flacco -- who is starting against Baltimore on Sunday for the Jets -- did in the 2012 season. Flacco's deal was set to expire, and he led Baltimore to a Super Bowl title before becoming one of the highest-paid players in the NFL.

Jackson, who has taken more hits (737) than any other quarterback since 2018, was asked last week whether he feels it's a risk to play with no guaranteed money beyond this season.

"It was a pretty big risk last season. The year before," Jackson said Wednesday. "I'm just playing football. Anything can happen. God forbid the wrong thing happens."

Jackson has proved to be one of the NFL's top playmakers and winners over the past four seasons. Since he became the Ravens' starter midway through the 2018 season, Baltimore is 37-12 (.755) with him and 2-5 (.286) without him. He was the unanimous NFL MVP in 2019.

But Jackson is coming off his most challenging season in 2021, when he threw a career-worst 13 interceptions and missed a career-high five games, including the last four because of an ankle injury.

ESPN's Jamison Hensley contributed to this report.