The question now is: How will they use them?
The Titans have started answering those questions here at the NFL owners meetings, but as coach Mike Vrabel and general manager Jon Robinson have both pointed out, things won't come into better focus until the team begins offseason work, and gears up for the 2018 season.
It's early, they said.
"I think we all have hopes and visions of what that might look like (with Derrick and Dion)," Vrabel said on Tuesday morning. "But I think until they get back and come in our building, and we start to practice and line up, I don't think we'll really know. But certainly we're excited about Derrick -- can't wait to see him come back. And then Dion, kind of incorporating himself into our team.
"… There's only one football, and there's a quarterback, and there's five eligible receivers. So I think everybody understands they are not going to get the football every single time. And Dion has been with other runners at other places he has been. So we're hopeful and confident that will continue in Tennessee."
The big and physical Henry led the Titans with 744 rushing yards on 176 carries in 2017, and he scored five rushing touchdowns.
The 5-foot-8, 195-pound Lewis led the NFL in rushing yards (625), with an average of 5.12 yards per carry in the last eight games of the 2017 season, and he led New England in rushing yards. Compared to all backs with 150 or more rushing attempts, his per-carry average of 4.98 yards led the NFL in 2017.
"In my mind, we've got a big running back. We've got a big first- and second-down back," Vrabel said of Henry. "Dion provides a different body type, a different playing style. So how the two will complement each other, I'm not really sure. But I know that one's got a certain skill set and another body type and one is a little smaller, probably a little quicker, and has a different running style.
"That may change every week. One guy may get 20 carries one week because of the defense we're facing, and one guy may get 25 carries, whatever it may be. But I think Derrick is a young player that we are excited to give the opportunity to, just like when you watch the Kansas City (playoff) game (when he ran for 156 yards)."
Later, Vrabel added more on the subject.
"I think they'll work together fine," he said. "They have both shown that they don't have to be the guy that gets 30 carries. Those 30-carry a game guys, I don't think they exist any more. It is a hard position to play. Dion has been in a position where there's been other guys, and he's been a great teammate. In some games he may have a bigger role, and in other games he may have a lesser role. But we're comfortable with those two guys going in."
Robinson and controlling owner Amy Adams Strunk also discussed Henry and Lewis from the NFL owners meetings.
"He is a guy who has really good quickness," Robinson said of Lewis. "He is a playmaker with the ball in his hands. He is really good in the passing game, out of the backfield. He runs hard. He might be small in stature, but he is big in effort and big in grit in trying to pound it up in there and make yards. And he is another guy who has had some adversity in his life with injuries throughout his career. He's been told he was too little his entire life to play football."
So what's the one-two punch with Lewis and returning back Derrick Henry look like?
"One is obviously bigger than the other one," Robinson said with a smile. "No, but I think they complement each other well. I think they are both fast players. I think they both have good quickness. I think stylistically they are different runners. Derrick can get it downhill, press the hole, hit the hole, and really turn it over and outrun people. He can stick it up there and run over people.
"Dion can make people miss. He can kind of get lost in the wash up in there and squirt out, and be good out of the backfield. … How the pace of the game is going, how the style of the game, how the defense is playing us (will determine when which player is on the field).
"We think we have two really different backs, but two really good backs – two starting level backs."
Lewis racked up 141 all-purpose yards against the Titans in last year's playoffs -- 62 rushing yards on 15 carries, and he also caught nine passes for 79 yards.
"Oh my goodness. Look at what he did to us in the playoffs. Ouch," Strunk said of Lewis. "We laughed about that when we talked on the phone. He seems like our kind of guy. What a duo that is going to be with Derrick (Henry) and Dion."
TitansOnline.com looks at the NFL career of former New England Patriots RB Dion Lewis. (AP Photos)