Adam Schefter reports that the Dallas Cowboys will release QB Tony Romo on Thursday, the first day of the league year. (0:54)

Tony Romo will soon no longer be a Dallas Cowboy.

The Cowboys will release the franchise's all-time leader in passing yards and touchdowns on Thursday, sources told ESPN, allowing him the chance to sign with another team if he desires while removing any doubt that they have the utmost faith in Dak Prescott.

Cowboys owner and general manager Jerry Jones' decision to release Romo was the result of a conversation between the two on Tuesday, league sources told ESPN's Ed Werder.

A source told Werder that Romo did not have to pressure Jones to release him before the official beginning of NFL free agency so he could pursue opportunities with another franchise.

Jones told Romo that he had waited to determine whether another team might offer the Cowboys something in a trade for the oft-injured quarterback. When that failed to occur following the NFL scouting combine, Jones told Romo he would release him and make him a June 1 designation, which will save the Cowboys $14 million against the cap this year.

Romo will still count $10.7 million on the 2017 cap and $8.9 million on the 2018 cap.

The Cowboys are visiting with veteran quarterback Josh McCown on Wednesday, who would replace Romo as the backup quarterback if he signs with the team.

McCown was one of the Cowboys' targets last summer after Kellen Moore broke his ankle in the first week of training camp, but the Cleveland Browns' asking price was too high. McCown, who turns 38 in July, was released by the Browns earlier in the offseason after a two-year run with the club.

The release of Romo, who turns 37 in April, does not come as much surprise, although it was a move that pained Jones because of the close relationship he forged with Romo over 14 years.

Tony Romo's Cowboys Rankings Tony Romo will leave the Cowboys as the franchise's all-time leader in passing yards and touchdowns. Only Troy Aikman and Roger Staubach won more games as a starter. DAL Rank Pass yds 34,183 1st Pass TD 248 1st QB wins 78 3rd -- ESPN Stats & Information

Prescott's play in 2016, which earned him Offensive Rookie of the Year honors, and the Cowboys' a 13-3 record, all but clinched the decision. While the Cowboys could have afforded the $24.7 million salary-cap figure, in reality paying a backup quarterback $14 million made little sense.

Romo's rise to the top of the Cowboys' all-time passing chart started as an undrafted free agent out of Eastern Illinois in 2003. He eschewed a larger signing bonus from the Denver Broncos at the time to join the Cowboys.

Then-coach Bill Parcells took an immediate liking to Romo; however, he did not throw a pass in a game until 2006. After replacing Drew Bledsoe at halftime against the New York Giants, Romo made the first start of his career on Oct. 29, 2006, against the Carolina Panthers, throwing for 270 yards and a touchdown in a 35-14 win.

He sparked the Cowboys to a 9-7 finish and spot in the playoffs, but that season ended when he dropped a snap on a potential winning field goal attempt against the Seattle Seahawks in the wild-card round.

In his first full season as the starter in 2007, Romo threw for a then-franchise-record 4,211 yards, a mark he would set twice more in his career, and a franchise record 36 touchdown passes. The Cowboys finished with the best record in the NFC (13-3) but lost in the divisional round of the playoffs.

Romo has a career record of 78-49, but he never was able to get the Cowboys past the divisional round of the playoffs in four playoff appearances. His 34,183 passing yards and 248 touchdown passes are the most in team history, but with Hall of Famers Roger Staubach and Troy Aikman combining for five Super Bowl wins, Cowboys quarterbacks are judged on championships.

Tony Romo is set to become a free agent on Thursday. Rich Schultz /Getty Images

Romo also holds team records for most 300-yard passing games (46), multiple touchdown pass games (79) and consecutive games with a touchdown pass (38). In 2012, he threw for a club-record 4,903 yards and on Oct. 6, 2013, against the Denver Broncos, he threw for a franchise record 506 yards. He owns the NFL record with a touchdown pass in 41 straight road games.

Back injuries started to slow Romo down. In 2013, he had two back surgeries, including a discectomy before the season finale. He suffered two transverse process fractures in 2014 but missed just one game in leading the Cowboys to a 12-4 record and NFC East title.

In 2015, he suffered a broken left collarbone against the Philadelphia Eagles and missed seven games. He rebroke the collarbone in his second game back and missed the final five games. The Cowboys went 1-11 without Romo.

After undergoing collarbone surgery last spring, Romo said his back felt as strong as it had in years, but on the third play from scrimmage in a preseason game against Seattle, he was awkwardly driven to the turf by Cliff Avril and suffered a compression fracture in his back.

Romo's absence allowed Prescott, the Cowboys' second fourth-round pick last year, to win the starting job. After losing the season opener, the Cowboys won a franchise-record 11 straight games. Prescott finished his rookie season with 23 touchdown passes and just four interceptions. He also set a team record for a quarterback with six rushing touchdowns.

Disappointed he would not have the chance to win the job back, Romo diffused any controversy with a heartfelt statement backing Prescott upon his return. He served as the backup for the first time since 2006 and saw action in just one game, throwing a touchdown pass on his lone drive in the 2016 finale against the Eagles.