Chris Mortensen weighs in on Jason Witten's retirement decision and what it would mean for the Cowboys. (1:48)

Dallas Cowboys tight end Jason Witten is on the brink of retirement after 15 seasons to join ESPN as an analyst for Monday Night Football, league and team sources told ESPN on Friday.

During a news conference to introduce first-round pick Leighton Vander Esch on Friday, Cowboys owner Jerry Jones said he had spoken with Witten several times this week. Jones did not address what he and Witten discussed and said the tight end still needed time to contemplate his future -- "at least through the weekend."

"He has some things to think about and discuss with his family from a professional perspective," Jones said.

Two sources said Witten's plans won't be final until he receives Jones' blessing, and one source allowed that Witten could always have a last-minute change of heart.

A team source said the Cowboys were aware of the possibility, but Witten was not making a final decision until he met with Jones.

Nevertheless, the consensus is that Witten's impressive football career is coming to an end.

Witten was not available for immediate comment. ESPN declined comment and has had no announcement to reveal its new Monday Night Football broadcast team.

Witten would leave the Cowboys as the franchise leader in games played (239), receptions (1,152) and receiving yards (12,448). He is third in receiving touchdowns (68) and is tied with Hall of Famer Bob Lilly for the franchise mark with 11 Pro Bowl selections.

Witten has the fourth-most receptions in NFL history, behind Jerry Rice, Tony Gonzalez and Larry Fitzgerald, and is only the second tight end in history to have more than 12,000 receiving yards, trailing Gonzalez (15,127) in that category.

Despite having signed a four-year extension in March 2017 and saying he planned to play beyond this season, Witten has been engaged in talks to become a game analyst with multiple networks, including ESPN, for several weeks, sources said.

Sources say Jones has been in the loop for a couple of weeks as to the possibility Witten could leave for such a job.

"I know this: The burn is strong inside me to play at a high level and to be a part of one of these groups of guys and one of the leaders to see this thing through and go try to compete for a championship," Witten said after the Cowboys' season-ending win over the Philadelphia Eagles on Dec. 31. "When I wake up tomorrow, that's where my focus will be on as I move forward.

"It hurts because you don't get a whole lot more opportunities at this, and I realize that. But rest assured that I'm going to do everything in my power to help us be better as we move forward. And I think it needs to be clear that it starts with yourself."

Witten was a constant at the captains' workouts at The Star, the Cowboys' facility, before the official start of the offseason program.

Jason Witten ranks 21st in NFL history -- and second all-time among tight ends -- with 12,448 receiving yards. AP Photo/Brandon Wade

If the arrangement is finalized, as expected, he will become the third former Cowboys player to work as a lead network broadcast analyst, joining Troy Aikman (Fox) and Tony Romo (CBS).

The Cowboys now must determine whether the tight end position becomes a priority for the second and third rounds of the NFL draft Friday night. James Hanna (knee) was placed on the reserve/retired list; the Cowboys still have Geoff Swaim, Blake Jarwin and Rico Gathers under contract.

Swaim's nine career receptions represent the trio's entire output. Witten had 19 games in his career with at least nine catches, including an 18-catch, 167-yard effort against the New York Giants on Oct. 28, 2012. The 18 catches are the most ever by a tight end and tied for third most in a game overall.

Witten, who played collegiately at Tennessee, was drafted by the Cowboys in the third round of the 2003 draft. The Cowboys signed Romo, an undrafted free agent out of Eastern Illinois, that same year.

Witten quickly became one of Bill Parcells' favorites, earning the Hall of Fame coach's favor by missing just one game as a rookie, despite a broken jaw.

Constant Cowboy Dallas Cowboys tight end Jason Witten ranks fifth in receiving yards -- and first among tight ends -- for a player who spent his entire career with one team. Player Rec. Yds. Team Larry Fitzgerald 15,545 Cardinals Marvin Harrison 14,580 Colts Reggie Wayne 13,345 Colts Steve Largent 13,089 Seahawks Jason Witten 12,448 Cowboys

To play against the Detroit Lions on Oct. 19, 2003, Witten stuffed rolls of quarters in his sweatpants so he could make his prescribed weight despite not being able to eat solid food.

It was the first sign of Witten's legendary toughness. He did not miss another game in his career, despite numerous sprained knees and ankles and other injuries. In 2012, he suffered a lacerated spleen in a preseason game against the Oakland Raiders but managed to get cleared medically hours before the regular-season opener against the Giants.

He caught only two passes for 10 yards, but coach Jason Garrett called it his favorite Witten memory.

"Forget 110 catches [in 2012], forget [the] Pro Bowl, forget all that stuff. When you tell the Witten story, I start with that one because I think he showed what he's all about," Garrett said. "What he's been doing for a long time in this league, and a great example for the rest of our football team and, really, for the rest of humanity and the whole NFL. That's how you do it. He's really a tough guy, he's an amazing guy and we're lucky to have him."

According to ESPN Stats & Information, Witten's active streak of consecutive games played (235) ranks second to punter Shane Lechler (254), and his streak of games started (179) is second only to quarterback Philip Rivers (192).

Witten turns 36 on May 6. He and his wife, Michelle, have four young children. In 2012, he was named the Walter Payton Man of the Year for his work in the community. His foundation has provided assistance for families and women affected by domestic violence; Witten was raised in a family that was torn apart by domestic violence.

ESPN's Todd Archer contributed to this report.