DETROIT -- On their fourth official play of the Falcons' first preseason game against Detroit, rookie Drake London crossed the field on an intermediate route with a defender right on his tail, and quarterback Marcus Mariota delivered a perfect ball for London to snare and turn upfield with. A Lions defender collided with him, he went to the ground along the Lions' sideline and he got up and made his way to his team's sideline.  

That impressive, seemingly innocuous play wound up being London's last of the evening. Five snaps including a penalty, and we had our one and only taste of the first-round sensation. The Falcons announced his knee injury would keep him from returning.

London stayed on the sideline through the first half, a very good sign, and was walking normally with a compression sleeve on his right leg after the game. Falcons coach Arthur Smith didn't have an update, only saying the team will know more this weekend.

It would seem as though London's injury won't do anything to scare Fantasy managers off from drafting him, but the lone drive by Atlanta's starters brought up a different concern. A throwback … or maybe a run-back is more appropriate.

Mariota ran on three of the Falcons' 12 plays, including from six yards out for a touchdown. And, according to Smith, none of them were by design – each one was an improvisational play Mariota dialed up by instinct.

"It's kind of part of how I play," Mariota said after the game. "… I'm not afraid to sit there in the pocket and do what I gotta do, it just kind of depends on what (the defense) gives me. … But if (running opportunities are) going to happen, that I gotta make plays that way, I'm more than willing to do it."

You might think Mariota's running might not mean anything. But the last time he was a regular starter he had multiple rushing scores four straight seasons and over 300 yards on the ground in three of them. And even when he was the backup with the Raiders, Mariota was used here and there as a change-up mobile quarterback. His legs are clearly a part of his game.

"You'd like to have guys who do that pull back," Smith said. "You're in preseason … but he can't help himself. … [H]e's another player that's got a lot of speed that you've got to defend sideline to sideline."

When Mariota runs, he's not throwing or handing off. It's not going to get to the level of a Michael Vick circa 2006, but it's going to take plays away from London, Kyle Pitts and the rest of Atlanta's offensive talent. At times it will in fact help them, because he'll leave the pocket to extend the play -- that happened to London on his 24-yard catch. But Mariota's history combined with his re-emergence as a willing runner will prove to be a double-edged sword.

Is now a bad time to bring up that Mariota has never averaged 31 pass attempts per game over a season? Or connected with a wide receiver for over 70 receptions or 1,000 receiving yards in a season?

At least Pitts can hang his hat on the big seasons Delanie Walker had with Mariota, including a 94-1,008-6 stat line all the way back in 2015.

Plus, there's no doubt that Mariota's aggressive style opens himself up to injury. We've seen it before, unfortunately. Falcons rookie quarterback Desmond Ridder had some very nice moments on Friday, but he's not ready to command the offense.

It stings because Pitts and London have some tremendous upside. But if the Falcons throw a little less and hand off a little less, there's not quite as much potential as Fantasy managers would want. It doesn't mean the Falcons won't be a good team, but they might not be great for our Fantasy teams.

Pitts remains the No. 3 tight end in my rankings, but London might not quite have the upside of other receivers in the No. 3 range. You may not want to sink a top-75 pick into him on Draft Day, even in PPR leagues.

It should also be mentioned that Mariota's rushing hurts the upside of the Falcons running backs. And that doesn't help the fact that the Falcons have a lot of players who can run the rock. Cordarrelle Patterson was a breakout last year who operated as the lead back on the very first play against the Lions, then didn't play again (Smith said the team didn't get into the right situation for him to see the field). Qadree Ollison and Damien Williams mixed and matched throughout the first few drives, then Caleb Huntley and Avery Williams got in before rookie Tyler Allgeier saw a few snaps to end the first half and play into the second quarter.  

Patterson's the only Falcons running back worth a top-100 pick; Allgeier may warrant a pick late if he moves up the depth chart – his blocking on Ridder's game-winning throw may give him more chances.

As for Mariota, he won't get picked in a one-QB league, but he does deserve some extra attention in leagues that can start two passers. He may not play 17 games, be it because of injury or because the Falcons will want to give Ridder some work, but when he is on the field, his rushing skills will afford him the chance to help out. Don't discount him on Draft Day.