Fantasy football research never stops, and roles change drastically from one week to the next. That's where our fantasy football mailbag comes into play.

Have a question about a certain player, team, strategy, or anything football? Shoot us a question on Twitter or send an email to Jim.Sannes@FanDuel.com, and we can talk anything fantasy football related -- even daily fantasy football.

Don't forget to check out our NFL remaining yearly projections, weekly projections, and our brand new DFS tools, which are available to all premium subscribers.

Now, let's answer some questions.

Email submission from Nikhil Tejwani:

So I have James White and Dion Lewis while my trading partner has Allen Robinson.Would you trade my duo of running backs for a buy-low candidate like ARob? A bit worried about whether or not Allen will ever show up but the new OC and fifteen targets last week makes me optimistic.

Because of both Blake Bortles' play and Allen Robinson's sudden decline in efficiency relative to his teammates, Robinson isn't necessarily somebody we want to target in trades at the moment. But when the price is James White and Dion Lewis, the scenario changes a bit.

Lewis started practicing for the New England Patriots last week, meaning the team must activate him within the next two weeks if they want him to play this year. Basically, Lewis should be back soon, which would make White unplayable in fantasy. But it doesn't necessarily mean that Lewis will jump right back into the meaty, fruitful role he had in 2015.

Lewis is coming off of several major surgeries, so he's not likely to jump right back in and play two-thirds of the snaps like he did when healthy last year. White leads all running backs in per-target efficiency, according to numberFire's Net Expected Points metric, so the team isn't handicapping itself by having him on the field. They can afford to ease Lewis back in, and that's detrimental to his fantasy stock.

With Robinson, we're not going to get the touchdown-bathing stud we had in 2015. But there's still value in a player with a 24.5% target market share in an offense that will have to throw the ball with regularity. There will be times when you can still feel good about plugging him into your lineup, and that may not be the case for either White or Lewis for a bit, making this a trade we should likely accept.

Cameron Meredith has played at least 80% of the Chicago Bears' snaps each of the past four games, so he certainly still has a role, and he is deserving of some fantasy attention. But with only four targets over his past two games, you can drop him if you need space on the bench.

As for Jordan Howard, you'll likely want to move him if you can. The Bears said before the game that they were going to ride the hot hand at running back, the kiss of death for fantasy value. Howard went bonkers in the game, which increases his chances of snagging a bigger role going forward. But he's far from a lock.

Even after Howard excelled in Week 4 and Week 5, the team leaned heavily on Ka'Deem Carey the following two games. Now, you've added Jeremy Langford back into the mix. While Howard has certainly out-performed Langford this season, that's another potential "hot hand" candidate. The Bears haven't shown consistency with their carry distribution at any point this season, and it's best to pounce and trade Howard when his value is highest.

Want to have your questions answered in our mailbag? Submit your questions by tweeting @numberFire or sending an email to Jim.Sannes@FanDuel.com.