A season ago, Bryant and Witten combined for 11 touchdowns -- half of Dak Prescott's season total -- as well as 132 catches and 1,398 yards.
The Cowboys are going with committee approaches at wide receiver and tight end to replace those two, but the biggest change in the passing game might be with the player already shouldering a large offensive role.
Running back Ezekiel Elliott.
"I'm ready for whatever they throw at me. Whatever they ask me to do, I'm going to go out there and do it. That's it," Elliott said. "All I want to do is go out there and win, so if they need me to do more, I'll do more. If they need me to do less, I'll do less. It's whatever this team needs. Whatever is best for the team."
What is best for the Cowboys is keeping Elliott involved.
When they made him the fourth overall pick in the 2016 draft, it was with the idea he would never have to come off the field. Despite carrying the ball 322 times in 15 games as a rookie and 242 times in 10 games last season, the Cowboys were mindful of not burdening him too much.
"Really that's probably been the guiding principle here the first couple years," coach Jason Garrett said. "We've given him a lot of responsibility as a runner, as a protector, so you've got to be careful about spreading him too thin when you have some other guys who can do those same kinds of things."
It is not just that he is now entering his third year and is more comfortable with the entirety of the job. It's that the Cowboys need him.
The Cowboys are hoping quantity at pass-catcher cancels out a Cowboys tradition of relying heavily on a No. 1 receiver. The hope is Allen Hurns, Cole Beasley, Deonte Thompson, Terrance Williams, Michael Gallup and Tavon Austin combine for one 1,000-yard season between them. The tight ends on the roster have combined for nine catches in their careers. All of them belong to Geoff Swaim.
"[Swaim] can be really impactful," offensive coordinator Scott Linehan said. "He's been very effective when we have thrown him the ball. You've seen it on screens and things we've done. I think he's going to be a guy that the quarterback is always going to have in his mind whether he's the first progression or not. But getting him the ball in the passing game is just as critical as when we hand him the ball. I think he's going to be picking up some of the slack."
Linehan's history suggests he will give a running back a chance out of the backfield.
In his final year as the Detroit Lions' coordinator in 2013, Linehan had two running backs -- Reggie Bush and Joique Bell -- catch more than 50 passes, and that came with Calvin Johnson catching 84 passes for 1,492 yards and 12 touchdowns. Bell actually had two seasons with more than 50 catches under Linehan.
In Linehan's first year with the Cowboys in 2014, DeMarco Murray had a franchise record 392 carries for 1,845 yards, but he also caught 57 passes for 416 yards.
Elliott has 58 catches for 632 yards and three touchdowns in the first 25 games of his career.
"If you look back to his rookie year, his second year, you still had Jason Witten, you still had Dez Bryant, you had Cole Beasley. You had guys that were effective and really, really good in the passing game," running backs coach Gary Brown said. "Now we don't have [as many proven threats], so now obviously we're going to lean a little bit more on him. These receivers we have are very underrated and they're going to do great things, but at the same time we're going to get Zeke in some situations where he can catch the ball out of the backfield and make things happen as well."
Elliott's biggest contributions to the passing game in his first two seasons has come on screens. He scored touchdowns of 83 and 72 yards on screens. His biggest gain as a pass-catcher in training camp so far has come on a screen.
Among the top running backs in the NFL, none compare to Le'Veon Bell. He has three seasons with at least 75 catches, including 85 receptions for 655 yards and two scores last season.
Brown says Elliott has a similar skill set to Bell. Garrett called Elliott, "a natural pass-catcher," and he can be isolated out wide in formations. But for the Cowboys to call on him regularly in 2018, Brown said Elliott needs to continue to develop as a pass-catcher.
"The word 'threat' only applies if he does anything, not if he doesn't catch a ball out of the backfield," Brown said. "He has to make problems for the defense. We believe he can do that. We're looking at him to be that way."
Without Witten and Bryant, he has to be that way.