Twitter mailbag: Duke Johnson to Dolphins?

The Miami Dolphins have a lot of big decisions to make in the coming weeks and months in order to improve on last season's 8-8 record.

Here are some questions on the minds of Miami fans:

James Walker: I've watched University of Miami running back Duke Johnson grow into a solid NFL prospect over the past two seasons. I like Johnson as a player. But I don't see him as a fit for the Dolphins, who already have a similar starting tailback in Lamar Miller. Miami needs a power running back to complement Miller, someone who can grind out those tough yards and thrive in short-yardage situations. Johnson is more of a speedy, home run hitter. Look for Johnson to get drafted elsewhere.

James Walker: Knowshon Moreno was expected to fill that power-tailback role that I mentioned in the previous question. But Moreno is too injury prone, which is the reason the Dolphins signed him to a one-year contract in 2014. Moreno suffered two knee injuries and an elbow injury during his short tenure in Miami last season. He will be 28 in July and has a lot of tread on the tires. Moreno is a solid player when healthy. But I expect the Dolphins to go younger at the position and find a power back who is more durable.

James Walker: There were plenty of debates in the comment section on Facebook and via Twitter over "Walker's Fab 40," which is expected. Ranking 40 players on any team will bring a variety of response. I expected some to agree and disagree, especially when it came to the top of the list. My criteria was simple: It is based on who are the best players for the Dolphins right now. Production last season is definitely a factor but it's not everything. For example, Miami left tackle Branden Albert started just nine games and came in at No. 1. Some thought starting quarterback Ryan Tannehill (No. 5) should have been No. 1 because he had a career season. But Tannehill is not the best player on the team.