Team owner Jerry Jones said he met with Witten on Friday and the decision hasn't been finalized at this time, per Brandon George of the Dallas Morning News:
"I've talked to Jason Witten several times this week, met with him a few hours ago and we've had great discussions. He has some things to think about and discuss with his family and he'll need a few more days of consideration. No final decision made on retirement."
Witten's $4.7 million contract bonus wasn't paid to him prior to retiring, per Mike Fisher of 105.3 The Fan.
After the Cowboys selected him in the third round of the 2003 draft, Witten became one of the most consistent tight ends in the league. He was named to 11 Pro Bowls and earned first-team All-Pro honors in 2007 and 2010.
Witten retires having set Cowboys franchise records in receptions (1,152) and receiving yards (12,448). He's also one of the most prolific tight ends in NFL history. According to Pro Football Reference, only Tony Gonzalez has more receptions and yards, while Witten's 68 touchdowns put him at sixth-best for the position.
There's no questioning Witten's production over his career, but he was showing clear signs of a decline in recent seasons. He hadn't cracked 1,000 yards receiving since 2012, and his 560 receiving yards in 2017 marked his lowest total since his rookie year.
Bleacher Report's Marcus Mosher questioned whether Witten's lack of explosiveness was hurting the offense as a whole:
"Witten is averaging just nine yards per reception this season. That's down nearly a full yard from 2016 and nearly two full yards from his career average of 10.8. Teams are playing more man-to-man coverage against Dallas and daring Witten to beat them. At this point in his career, it's just not something he can do consistently.
"This decline should have been expected, and in fact, the Cowboys are fortunate that it didn't come sooner. Witten can still contribute as a blocker and as a reliable receiver in certain situations, but Dallas needs to find a different way to beat man coverage in the middle of the field in 2018. Unfortunately, the answer likely won't contain No. 82."
Still, Witten's departure will leave a void in the passing game. He hasn't missed a game since his rookie year, so the Cowboys haven't had to give much thought to the tight end position for over a decade. Because of that, Dallas may have to look outside the team for Witten's replacement.
James Hanna announced his retirement earlier in April, and Geoff Swaim has not emerged as a solid pass-catcher. Undrafted free agent Blake Jarwin saw only a limited role in his first season.
The 2018 draft may be Dallas' best bet to find a long-term successor to Witten. Mark Andrews, Mike Gesicki and Dallas Goedert are among the top tight ends remaining in this year's draft class, and any one would be a solid addition for the Cowboys offense.
For Witten, he should start getting his Hall of Fame speech ready. As one of the best tight ends of his era, the 35-year-old is a look for enshrinement in Canton, Ohio.