The Miami Dolphins prepare for their third and most important preseason game when they host the Dallas Cowboys this week. Therefore, it’s a good time to re-open the mailbag and see what’s on the mind of Dolphins fans.

@JamesWalkerNFL Is Shelley Smith a serviceable starter or solid (Garner-esque) backup? #DolphinsMailbag

— james (@jamesandretti) August 20, 2014

James Walker: Good question, James. I don’t want to make sweeping observations in August. But I do have concerns about Shelley Smith as a full-time starter from what I’ve seen in training camp and the preseason. For starters, Smith is not a mauler. He’s not the biggest or strongest offensive lineman, and Miami’s biggest problem right now is getting push from the offensive line in the running game. I don’t think Smith fixes that problem, especially against some of the NFL’s best defensive tackles. Two former Pro Bowlers will face Miami in Week 1 and Week 2 in Vince Wilfork (New England Patriots) and Kyle Williams (Buffalo Bills), respectively.

@JamesWalkerNFL Have you seen any positive changes in the leadership style of Joe Philbin? Is he growing as a leader of men?

— Danny Renn (@DannyRenn) August 20, 2014

Walker: Absolutely, Danny. Joe Philbin has worked hard on his leadership after all that went wrong last year with the bullying scandal and late-season collapse. Much of the change started at the owners meeting in the spring, when Philbin was surrounded by 31 other head coaches and leaders in the NFL. Philbin took a lot from those several days in Orlando and he’s been building better relations since with his players. He’s been communicative, more available and looser with his players. Often these things help players go the extra mile for an NFL coach. It’s more than just good Xs and Os.

@JamesWalkerNFL Is there any indication that Billy Turner is going to start getting first team reps at that RG spot?

— Robby Cerniglia (@Sir_RoberT8) August 20, 2014

Walker: Not at all, Sir Robert. Billy Turner, Miami’s rookie third-round pick, got a brief look during spring organized team activities and summer minicamp. But he’s not in consideration for the starting right guard job. Turner is actually playing as the backup left guard, which is the side he’s used to after playing left tackle in college. Turner has good size and a mean streak. But he’s still raw, and the Dolphins can’t afford that right now. They have enough questions on their offensive line.

@JamesWalkerNFL James IYO are the 3 best LB's on this roster playing getting the 1st team reps?

— reconrican (@ecantres) August 20, 2014

Walker: This is a tough question, ECantres. As you probably know, I have been critical of Miami’s linebacker play dating back to last season -- and for good reason. I’m still not sure this group is that improved, because you have the same three starters. Miami’s hope is the position change between Dannell Ellerbe and Koa Misi will help both make more players. I do like rookie backups Jordan Tripp and Chris McCain. Both will make the 53-man roster and both have potential. But to say they’re better than three starting veterans and ready to start a 16-game season is premature.